Chin Ho must face the fact that his daughter, Alia, is in love with the son of a local criminal under investigation, and that she plans to get married to him.

An aging jewel thief steals from rooms at Waikiki hotels, and taunts Five-O by leaving a trail of clues behind.

An investigation into a murder is sent off track through the modification of computer information, and Five-O must use the latest technology to rescue the case.

Three women desperately in need of money take to armed robbery of tourist buses as a way to raise some quick cash.

When a psychotic man kills his doctor, Five-O must use a unfinished painting to gather clues to his whereabouts.

McGarrett must prevent a mob war by tracking down an unknown hitman and his intended target.

A road accident starts the trail towards a plot to use SAM missiles to bring down a VIP jet plane.

When a singer witnesses a murder committed by a racketeer, Five-O has to protect her until she can give evidence, but this is not an easy job...

A vice-principal enlists the help of his students and a submarine to smuggle drugs.

A writer who specialises in solving mysteries uncovers the body in a seven year old case, but it raises more questions than it answers...

A disturbed young man steals nerve gas to use against a visiting royal family as revenge for the death of his father.

When an elderly importer who was a World War II Japanese spy is killed, Five-O seeks his killer.

A crooked contractor and a buildings inspector are under suspicion after the new Global Trade Center in Honolulu goes up in flames.

Criminals threaten to use a special type of moth to wipe out the sugar cane on Hawaii and destroy the industry.

Ben Tanaka, a well-known ecologist, seems to be behind the kidnapping of a wealthy land developer's wife, but all is not as it seems and a conspiracy gradually reveals itself.

The murder of island prostitutes seems to be linked to an extortion racketeer who is determined to make a return...

When $10 million goes missing from a crimelord, the culprit seems to be dangerously close to home...

After a government agent is murdered, McGarrett must identify the traitor in a scientific facility.

When an astrologer visits McGarrett to inform him of a murderer with a terrible temper, his antagonism lessens when her assumptions seem to be partly true.

An assassin who doesn't know he's an assassin? Sounds like a punch line from "The Naked Gun," but it's the story of this episode, where a diplomatic courier with a briefcase chained to his wrist is hypnotized and programmed to rig the case with a bomb. When Danno goes undercover to ferret out the assassination ring, he himself is brainwashed and programmed to kill McGarrett.

McGarrett is the lone hold-out in a trial where the guilt of the accused seems certain.

Steve is framed on the orders of a gambling syndicate, and becomes involved with a woman who is part of the case.

Five-O must deal with the plans of a Neo Nazi organisation to kill Bobby Tamara, the ""Hawaiian Kennedy"".

When a street robber claims that he stole King Tutankhamun's mask for fun, McGarrett suspects there is more to the case than simple robbery.

McGarrett assists a convict in his escape, so that he can go back to his gang and provide Five-O with inside information.

Danno is surprised when he bumps into a former flame and even more concerned when she seems to be involved in criminal activities.

The death of a prominent politician reveals a strange love triangle.

When a preacher is attacked by a man convinced that he is responsible for his wife's death, Five-O investigate more closely and discover some less than godly motives.

Two rival mobs attempt to take control of the disco scene in Honolulu.

The rival gangs are on the brink of all out war, and Five-O must struggle to stop them.

When a robbed bank vault shows no signs of break-in, an inside job seems the likely solution. McGarrett's trail of clues leads him back to the builder of the vault and his wife...

Millicent Shand returns and claims that her niece's husband has faked his own death in order to get his hands on $500,000.

A vacationing heiress seems unconcerned when McGarrett warns her that someone is after her ruby.

When a photographer takes a picture of a politician making a deal with an underworld figure, he tries blackmail. However, he is not prepared for the ruthless nature of the mobsters.

A private detective is rescuing girls from prostitution, and using the opportunity to kill the pimps as well.

When the son of one of Steve's friends dies of an overdose, he goes after a doctor that he suspects of over-prescribing drugs.

The hunt for a high-rise killer is made more difficult for Five-O when a journalist offers to share his profits in exchange for the killer's story.

When a woman dies due to heroin packets bursting inside her and the Governor is implicated, McGarrett and Danno head off to Singapore to discover a smuggling operation.

Five-O must close the heroin smuggling operation to exonerate the Governor and catch the figures behind the scheme.

McGarrett finds himself stymied when Hawaiian nationalists and local underworld mobsters clash over a union election.

Labouring under a ban on cooperation by native Hawaiians because of a Kahuna, McGarrett must try to prevent war on the streets...

When the husband of a policewoman is gunned down by opportunist robbers, she resolves to catch them any way she can.

A group of high society men set out to see that justice is done - the catch being that it is justice on their terms only...

Jessica Humboldt, an astrologer and friend of Agnes DuBois, comes to McGarrett with news that a forthcoming match will be disastrous for a boxer. McGarrett must overcome his suspicions and crack the case.

Tony Alika and Guido Marioni, killer of Kimo's family, together hatch a plot to frame and embarrass the Five-O team by making them look stupid or corrupt.

When a woman is stalked by a strange figure, she seems to be seeing things and her friends are worried as to her mental health. However, events prove her case and an accomplice is revealed...

When two surfer bums use a gun to rob a shop, it starts off a trail of death and misery involving children, politics and blackmail.

A group of terrorists capture a female officer and use her to further their aims, and McGarrett and the team must find a way to take them out without endangering the life of Officer Dean.

A young man on vacation has strange visions that lead him to the site of an old murder and help him discover a lost family.

When two healthy young people die mysteriously, local traditions prevent post mortems, and a strange conspiracy is gradually uncovered when Truck seems to fall under the power of a Kahuna...

When a rich socialite is kidnapped, her husband insists that Five-O stay out of the case. However, his reasons may not all be on the level as events take a series of twists and turns...

McGarrett and Kimo must stop a gang of trained assassins from disrupting a meeting of energy ministers.

A aging crook decides to use dollar bill printing plates he made to raise cash for a charity, but he fails to realise the trouble that this will cause.

McGarrett is suspicious of an aide who arrives in Hawaii to retrieve millions of dollars held in trust for a Southern Asian state and he must prevent a daring gold robbery.

A gang of clever students use radio-controlled planes to execute the theft of Queen Liliokalani's jewels.

The murder of a Nazi-hunter and discovery of a World War II medal set McGarrett and the team on the trail of a Nazi war criminal living in Honolulu...

A group of seemingly harmless birdwatchers are the target of a vendetta. Five-O must discover why they were a target and stop any further violence.

A politician trying for the Senate is weakened by the murder of the man who is blackmailing him.

The series concludes with the final showdown between McGarrett and Wo Fat. Three scientists have gone missing. They have one thing in common: they all attended a symposium that discussed a possible space-based, laser defense system. McGarrett impersonates a fourth scientist, Dr. Elton Raintree, who attended the same gathering and is soon abducted. Wo Fat is behind it all and wants the scientists to complete their work and produce such a device.