Aeronautical Engineer Steve Douglas and his youngest son Chip face a parallel problem -- how to rid themselves of two designing females: Widower Steve is introduced to attractive and eligible Pamela MacLish, and is pursued by her because she wouldn't mind being the new Mrs. Douglas. Steve's youngest son Chip, aged eight, has similar problems with his classmate Dorine Peters, who would love to be his steady girlfriend. Pamela decides to call upon Steve with some leftover cake from their dinner, only to be met with a rambunctious houseful of children. Michael O'Casey, Steve's father in law, affectionately known as 'Bub' attends to the household chores. The eldest son Mike, aged eighteen and named after his Grandfather, is talking on the telephone, while middle son Robbie, aged fourteen, plays with the family's shaggy dog, known as Tramp. Before long Steve is accompanying Pamela and Chip to Chip's grade school dance. Chip takes it upon himself to give his father some sonly advice. Me

When Bub steps on the toes of each grandson in turn, Steve is about to rebuke him when the household returns to normal once again. Being chief cook, dishwasher and housekeeper to three boys is not fun for a grandfather as Bub soon finds out.

A Missile launch, sleeping in and Daylight Saving make for an interesting Monday morning. The Douglas household is a chaotic affair of lost indian arrow heads for Chip's turn in show and tell at School, Robbie's missing trumpet and some important lost plans of Steve's that Mike has nearly burned in the incinerator.

When Chip announces Tramp is the father of six puppies, Steve is concerned because he has never explained the cycle of life to his son. But before long a confused Chip thinks that his teacher is going to marry his father.

Steve and Bub are both called out of town and Mike urges them to leave him in charge, only to find the role of mother hen harder than it looks. His worth is really put to the test when he learns that Robbie and Hank have been taken to hospital after an accident at school.

Two dates, confused phone calls and name mix-ups create a tangled evening for brothers Mike and Robbie, when each get's the other's date. Mike gets a shock when he picks up a fourteen year old, while Robbie nearly croaks at the sight of his 'older woman'.

Bub reads an article in a magazine which is directed at bored homemakers and he begins to think that he fits the description. Steve warns him that he should control his Irish temper as it could lead to the demise of his position should he find one.

Mike faces disciplinary action at the hands of the Board of Regents and the Dean of the College for a wayward fraternity prank in which several of the students have created a foot-print mould which bears a remarkable resemblance to the hippopotamus.

Two of Bub's cronies who are visiting for their usual game of pinochle, accidentally get an earful of the family's woes. Their mysterious interjection to try and solve the problems, leaves Steve and the boys quite baffled.

Steve is going on a business trip to Japan and thinks he might as well take his family along with him. Mike gets involved in a new romance with another beautiful girl named Kimiko and suddenly he forgets his girlfriend back home.

Chip and his friend Sudsy see a Halloween spook carrying a candle in the neighbor's vacant house next door while out trick or treating, and are frightened out of their minds, but Steve and Bub will not believe them.

Steve is in too big a hurry to get home to his family and spread the good news of his upcoming business trip to Bolivia, but hurts his back by throwing out his sacroiliac and is convinced that there is only one doctor who can help him.

The members of Robbie's high school wrestling team need higher grades to remain eligible, so they choose Steve as their tutor. Soon the house is quarantined for Diptheria, and when Bub doesn't get his long-awaited rendezvous with ""Old Roy,"" the biggest catch in the lake, watch out boys.

The Douglas family inherit a castle in Scotland from their Scottish Grandfather and the whole family descends upon Sheehan Bridge to see it. Not only does 'The Castle' turn out to be an entire village pub in the highlands, but other members of the clan give them a freetly welcome.

Chip and his new sidekick Ernie find some old treasure maps but get lost in the woods when they go treasure hunting, causing the family's plans to be changed when they have to go looking for them.

Steve is chosen to act as nursemaid for the attractive daughter of a visiting Danish dignitary who turns out to be only 17. The girl's energetic idea of fun brings Steve to his knees, as he searches desperately for a substitute escort.

Mike and Sally try to discover the truth about marriage from two of their recently wed friends, and think twice about getting married and having babies when they help another friend's expectant wife whose time has come.

Bub wants to get back to the greasepaint, so he swaps jobs with an actress friend at the Playhouse theater who longs for a normal home life. Each is so envious of the other's life that they agree to switch roles for the remainder of the company's season.

Kimiko, a Japanese girl Mike met in Tokyo last year comes to town to test her old feelings for Mike before she can be sure she loves another. Although Mike is now engaged to Sally, could he still feel something for her?

Disciplinarian Mrs. Proctor, Robbie's awful history teacher, breaks a leg and the replacement they receive is even worse. She is a charming, but inexperienced girl who earns her first battle star when she first encounters Robbie's class.

Mark Twain's stories inspire Chip, Ernie and Melinda to re-enact the adventures of Huckleberry Finn, Tom Sawyer and Becky when the youngsters run away from home to the river where they find a few adventures of their own.

Steve sails aboard the S.S. Carolina in order to establish a business contract with a firm but his task is complicated by Robbie who has a vacationing job as a steward onboard the same liner. They both find that business and pleasure do sometimes mix.

Bub decides to use his winning raffle ticket to take the Douglases to Ireland to visit his relatives. While in the village of Farnsea, they stay with his redoubtable 103 year old Aunt Kate and Cousin Mickey.

The Douglas family continues to revel in the fun in the Irish village of Farnsea, ruled by the formidable Aunt Kate. Steve realises that her wisdom is helpful when Mary Kathleen Connolly becomes infatuated with him.

Chip and Ernie get an interesting lesson in honesty, and dishonesty from the school bully, who volunteers an insight to the underbelly world of swiping school lunches. Chip becomes bewildered by the differing standards of honesty among those he knows and Steve must do his best to sort out the problem.

Bub decides to leave for an Irish holiday to help his formidable Aunt Kate celebrate her 104th Birthday in Dublin. Son-in-law Steve eagerly offers to do the housekeeping, rashly declaring that if all women organised their work efficiently, it could be done in just a fraction of the usual time. A belief which is hardly borne out by his own demonstrations.

With Bub permanently away in Ireland, Steve finally resorts to domestic assistance and the Douglas home is afflicted with a fiery dragon of a housekeeper named Fedocia. When Steve is desperately trying to solve the problem of getting rid of her the situation is saved by the arrival of Bub's younger brother Charley, a recently retired Ship's cook on leave. With Steve away on business and Charley about to leave for San Francisco, Chip is unhappy that he won't have a parent to come to his school's Open Night. The family soon learns that Charley's crusty disposition masks a soft heart.

A young engineer finds his lost half-Korean daughter who is staying temporarily at the Douglas House. But Uncle Charley finds that she exhibits more the cunning of the orphanage where she was found than the wisdom of the orient.

Steve's plan for an Hawaiian holiday is cancelled when Chip develops a case of bronchitis, so Charley and the boys plan to bring Hawaii to him in the form of a luau in the garden complete with ladies that he would undoubtedly have met on board ship.

Charley refuses to believe that a polite and quietly dressed man is in fact the last Chief of Owahnanee Tribe and his disbelief is deepened when the Indian asks for permission to visit their Tribal Burial grounds which just happens to be the backyard of the Douglas House.

Mike and Sally finally get married and leave for the East where Mike has a job as an assistant college psychology instructor. Robbie happily moves into Mike's old room. When Uncle Charley notes that they may soon be calling Steve 'Grandpa' he becomes somwehat concerned about growing old and calls up his former girlfriends. Robbie, now a college man, offers to help his father make friends with younger women, and while pretending to be disinterested, tries a few of his suggestions. When it is learned that Ernie must return to an orphanage, because he will not be allowed to accompany his foster parents in their move to the orient, Chip invites Ernie to move in permanently, giving Steve three sons once more.

Steve explores the possibility of adopting 10-year-old Ernie but runs into antagonism from Uncle Charley, who can forsee nothing but more work with a new boy to take care of. The family desperately wants to adopt the boy and Robbie decides that Steve must make a play for the lovely Miss Coulter. Her boss comes to inspect the house just as the boys have made a shambles of the place. At eight the next morning, Miss Miller returns. She inspects the house, spic and span now, and ushers in a happy Ernie, who is to stay on a temporary basis.

Ernie's adoption into the all-male Douglas household is threatened by a regulation that there must be a lady of the house. Steve again makes a request to adopt the child, but Misses Coulter and Miller of the adoption agency, say they are powerless to change the regulations. Miss Miller has a brilliant idea, however, and soon the family is appearing before a judge who decides that housekeeper Uncle Charley can legally be designated the 'lady of the house'. Charley approves if this fact is kept secret and Ernie is enthusiastically welcomed into the family.

Steve Douglas turns a business trip to Hong Kong into a vacation for the whole family. Uncle Charley, who once lived in China, is reluctant to visit modern Hong Kong, for apparently he still carries a torch for a beautiful girl he knew in the 1930s.

A boy who looks just like Robbie almost ruins his reputation by driving around on-campus and inviting strange girls to kiss him, before the deception is uncovered. Finally, both boys and their parents are brought to the dean's office.

The Douglas family returns from a trip to Britain and as the family watches home movies of their vacation, the amateurish footage reveals the reason for Steve's current moodiness: He is still carrying a torch for a lovely widow.

On a visit to Hawaii, Robbie falls in love, Ernie almost gets arrested and Uncle Charley is pursued by an old girl friend from 1945, who weighs 200 pounds now. Charley thus finds it necessary to stay in hiding until the plane leaves for home.

The Douglases move to California, where at first they are depressed to find the residents as chilly as the weather is warm. Robbie enrols in the University and is totally captivated by a blonde girl, and Uncle Charley is initiated into the rapid-fire procedure of shopping in supermarkets. The family begins to feel that their next door neighbors represent the characteristic stand-offishness of all Californians until they discover that they moved into the neighborhood the day before they did.

After advice from his father who tells him it isn't right to tie himself down to one girl, Robbie Douglas, intending to break off his romance with Katie Miller, ends up proposing to her. Soon his heart over rules his head and he buys an engagement ring and sets a wedding date.

Robbie and Katie pick a wedding date two weeks off. Katie's sorority sisters decide to do some private investigating on their own. Prospective groom Robbie then undergoes the complete once-over by his fiancee's family and runs the gamut of numerous cousins, aunts and a crotchety grandmother.

The day before her wedding Katie Miller feels she faces complete disaster. When Robbie tries to console her, she flares up at him and after a short argument, the pair declare the wedding is off. Of course, Grandma Collins thinks otherwise.

Early on his wedding day, Robbie Douglas and his family are peacefully oversleeping. They awaken just in time and scramble madly to get ready as Robbie and Katie are soon married amid traditional confusion and tears. The lost family dog, Tramp, returns in time to join the family in the front pew.

Chip Douglas is so nervous about taking his driving test that his new sister in law Katie decides to help by taking the test with him. Soon after they both get their driving licenses the family car collects a big scratch, but neither will plead guilty.

Robbie goes to Camp Roberts for two weeks military reserve training. At home, Steve becomes alarmed when he sees Charley's card telling him that he and the boys who are camping at Yosemite, plan to look Robbie up at camp. But he arrives too late to divert them and one-by-one each member of the family is inadvertently caught as a military prisoner.

Dressed as a chorine named Apple Annie at his Lodge 'Frolics' night, a weary Uncle Charley awakens from a nap after a matinee performance and is forced to walk home and is arrested by the police for hitting a flirtatious man.

Ernie remains at home with Uncle Charley while the rest of the family travel to various locations. Charley invites an old friend to dinner, believing him to be down and out. However, Ernie immediately identifies their guest as a famous television sherriff and he invites the two to the studio.

Uncle Charley persists in singing an old song about a guy who steals his best friend's girl. Chip listens with some sorrow but there is a misunderstanding that almost ruins the friendship between Ernie and his pal when Shorty sees Ernie walking to the movies with a new girl in the neighborhood.

While the family is doing some spring cleaning, Katie faints behind the couch. Soon her mother's intuition brings her to the house and she announces that Katie is going to be a mother. Once it is confirmed by a doctor, the family dotes on Katie, but seems to ignore the father to be.

Controversy erupts in the Douglas household over the selection of a doctor for Katie during her pregnancy. While Robbie and Katie want to choose their own doctor, Katie's mother insists on making an appointment with the Miller family doctor. Meanwhile, Steve stands in for an absent Robbie at his first baby class.

The baby stirs inside Katie and Robbie feels its movement and suddenly sheds his youthful ways to become very much the sober and altogether too serious expectant father. Meanwhile, fatherhood is taking a different approach when Tramp's puppies to the next door neighbor's dog Francis, are about to be born.

When Robbie and Katie announce that they might hire a baby nurse, Uncle Charley is confident they will ask him. When they don't, he embarks on a marathon of baby sitting so he can learn the ropes by hiring himself out as a professional baby sitter.

The day -- or rather the night -- of the big event finds expectant mother Katie quite calm, and Steve and Uncle Charley quite the opposite, and a hapless father to be off on Army manouvres. At the hospital, Katie gives birth to identical triplet boys and Steve must adjust to the fact that he is a Grandfather, three times over.

As the triplets come home from the hospital their names are announced by the happy parents: Robbie Jr, Charley and Steve II. Their father Robbie finds that he is totally unprepared for all of the attention that the infants attract.

It may not be poker, but nine in the Douglas family is a full house. Feeling somewhat responsible, Robbie decides to quit school in order to pursue work full time and find a new home for his family. A wise school counsellor takes steps to discourage the move. Meanwhile Steve designs some plans for an extension to the house to accomodate the babies further.

The contractor that Steve hires to add a baby alcove to Robbie and Katie's room leaves much to be desired. He displays all the charm of a top sergeant and is putty in Katie's hands, but is exasperatingly gruff and non co-operative to the males in the Douglas home.

Steve meets an attractive widow who seems to be very interested in him but suddenly she turns cool towards his intentions. The family does its best to give the impression that Steve isn't really as old as he seems.

Although Katie confidently calls the look-alike triplets by name, other members of the family doubt her accuracy, and when Steve helpfully bathes them, she admits that she can no longer tell them apart because he washed off the inkdots put on their feet. They must be taken back to the hospital for proper identification.

Steve's old Chinese friend transfers to Los Angeles and happily renews his friendship with the Douglases. He confides in Steve and Charley that he is concerned about the man his daughter has married - an aparently aimless hippie with long hair.

When old Bryant Park friends move into the neighbourhood, they renew their friendship with the Douglases at a family barbecue where Steve is cast in the role of marriage counselor by the eldest son who turns to him for help in saving his marriage.

Robbie and Katie move into an apartment on the next block and widower Steve Douglas becomes the target of Katie's relentless matchmaking. However, Steve meets a remarkable woman in a high school corridor and the two are quickly attracted to each other.

Robbie needs to talk to his dad-who seems unreachable

The whole Douglas clan conspires to encourage Steve's romance with the lady in question, Barbara Harper. After dinner, Steve and Barbara go back to her house where Steve is predictably nervous around her. They are both serious about their relationship, but neither of them realizes it.

Everyone (Except Barbara) knows Steve is going to propose to Barbara

With the ring finally on her finger, Steve and Barbara's engagement is exciting for everyone except Barbara's five year old daughter who isn't sure she wants to share her mother. Meanwhile, Barbara employs her considerable store of diplomacy in an effort to gain acceptance by Steve's family.

Steve and Barbara have different ideas on how their wedding should go.

After a series of events at which the Bride and Groom wonder if they are doing the right thing, Steve and Barbara have an argument serious enough for them to consider cancelling their wedding.

On Steve's wedding day the groom is predictably nervous. Recalling certain mishaps from his own big day, super efficient Robbie determines that his own father's wedding will be perfect and after a few hours of hectic, last-minute preparations, Steve and Barbara are married in a simple church ceremony.

Steve and Barbara's Honeymoon in a remote fishing village is bustling with hordes of other, younger honeymooners. They end up counselling several couples who are not adjusting to married life. When a bottle of champagne arrives from the family back in Los Angeles, the other honeymooners realise that Steve and Barbara are indeed honeymooners as well.

Hoping to renew her funloving friendship, Steve's old girlfriend from Bryant Park, who is now a rich divorcee, comes to town and gives Barbara a few jealous moments.

Robbie is asked to be the best man at the wedding of an old friend from Bryant Park. He decides to go back a week early to show Katie around the town where he grew up but ultimately makes a disappointing visit when he realises that time and years do change things.

A Special time consuming project keeps Steve and son Robbie so pre-occupied that they are tired when they arrive home. After the project ends, the co-workers throw a celebration party and when Barbara and Katie arrive with supper for their hardworking spouses, and see a party in full swing, they storm out.

Chip begins studying with a pretty co-ed whose disciplinarian father wants to know why her new friend is spending so much time with her. Meanwhile, on the eve of Steve and Barbara's first wedding anniversary, Dodie announces she is throwing a surprise party, but neglects to tell everyone when or where.

Uncle Charley and Barbara suspect that Chip and Polly are becoming serious about one another. Polly, unhappy at home because of her father's strictness, is afraid of losing Chip because of her parents' meddling. She asks Chip to elope, and taken aback, he asks his father for advice.

Barbara is flustered when she receives a phone call from a former college suitor, and is very apprehensive when Steve invites him to dinner. The entire family is anxious to meet her old flame, thus compounding her uneasiness.

Chip delights Polly with an expensive locket for her 18th Birthday and after their vague conversation, he thinks he's agreed to go steady, but Polly tells her mother that she has become engaged. Perturbed by her husband's probable reaction, Mrs. Williams arranges a luncheon to judge the seriousness of the matter.

Chip and Polly open a joint bank account and Chip takes on a box boy job at a supermarket to accumulate money for their future marriage. Later after she's had an argument with her father, Polly comes to the Douglases with her packed suitcase, but when Chip turns down the girl's offer to elope, she storms out.

Dressed as a cat for a costume party at the home of his employer in Bel Air, Steve goes for gasoline when his car stalls but the police arrest him as a burglar. Meanwhile, Polly notes that there is so much love in the Douglas household, that she just has to become a part of it.

Chip asks Steve's permission to elope, but before he grants it, he insists Chip give Mr. Williams the courtesy of asking his approval too. Chip goes to see Mr. Williams only to have him accusingly flaunt a private detective's report. Realizing that Polly's own father had hired a man to trail them, he storms out before asking for her hand.

Following their elopement to Las Vegas, newlyweds Chip and Polly are beset by nothing but trouble. The universal joint in their car gives out and they have to be towed into town. The hotel where Steve and Barbara stayed is no longer for honeymooners but for singles, and the newlyweds must spend their first night in separate rooms.

After Chip and Polly return from their honeymoon they spend a few days at the Douglases. Soon they move into their own college dormitory, and bridegroom Chip faces a father in law who refuses to speak to his newly married daughter.

Chip becomes violently ill after eating Polly's cooking, and she learns from the family that Chip is allergic to some of the foods she's been preparing. Distressed, she feels it would be better for her husband if she left him.

Barbara leaves Ernie in charge of looking after Dodie after she has to go shopping. However Dodie goes to her friend Drucilla's house, and when Barbara returns he cannot remember where she is. After Dodie is found, Barbara sends them both to their rooms for the day. Then Ernie and Dodie rebel when they feel that they've been unjustly punished.

Rob is laid off from work, but decides to move with Katie and the boys to San Francisco to accept a job at another company. They move into an apartment and meet several other tenants. One of them suggests Rob is always tired from the burden of supporting his family. Feeling disheartened by this and other remarks, Katie thinks that Rob doesn't want her and the triplets anymore.

Steve's look-alike Scottish nobleman cousin Fergus, comes to America looking for a bride to take back to his hometown of Sithian Bridge and moves in on the entire Douglas family, much to the dismay of Uncle Charley.

When Uncle Charley learns that Fergus is looking for a wife to take back to Scotland to provide him with heirs to carry on the family name, he takes out an ad in the local newspaper in an effort to rid the Douglas home of his nemesis.

Steve's Scottish cousin Fergus, after only one date with Bowling Alley Cocktail Waitress Terri Dowling, proposes but gets turned down by her. She feels inadequate to return to Scotland as royalty, but is eventually persuaded by Steve.

The wedding day for Steve's Scottish cousin and bowling alley waitress Terri Dowling finally arrives amid the traditional confusion and tears. They leave for a three day honeymoon in Las Vegas but Uncle Charley is worried about the lack of thankyou from them.

Uncle Charley leaves for a week's vacation in San Francisco but meanwhile, birthdays disrupt the Douglas household, when Barbara, Katie and Polly turn against their spouses over the men's apparent oversight.

Barbara's natural enthusiasm bubbles over into an embarrassing evening for Steve and some of his business associates. Barbara explains to Steve that adrenalin gets her going in competition, and she is apprehensive when he is asked to play in his work's bowling team for fear she will make him lose concentration.

Katie Douglas takes a job singing in a small coffee house, but both Steve and Charley have their doubts about the man she is going to work for. After meeting the owner's wife, they realise she is in very good hands.

Katie's triplets are spotted by a talent scout for a production company and are selected to appear in a television commercial. The temperemental Director yells when the boys misbehave and make a shambles of the studio. Grandfather Steve is asked to replace the actor doing the same so the boys will feel at ease.

Steve suddenly becomes accident-prone when his youngest son Ernie tries to discover by graph and observation how the moon's lunar phases affect people's behaviour.

Katie becomes disillusioned about life without Robbie, and seriously thinks about divorce after speaking with another of the wives in the same situation. Meanwhile, Dodie and her two pals campaign to Barbara to let them have a slumber party.

Steve's boss Bob Anderson and his wife share 'Where-did-we-go-wrong?' panic as they struggle to communicate with their son; Steve and Barbara are the counselors. The teenager is rude and disrespectful to his parents but his insolence doesn't bother them nearly as much as not knowing if he is taking drugs.