Fielding Mellish (Woody Allen) es un torpe y tímido catador de productos que, abandonado por su novia, la sensual y atractiva Nancy, decide cogerse unas vacaciones y pasarlas en la pequeña República de San Marcos. Pero lo único que consigue es verse envuelto en un sinfín de líos burocráticos en un país dominado por la guerrilla. Todo se complica aún más cuando, después de la conquista del poder por los guerrilleros, su líder se vuelve completamente loco.

Told in flashback, Depression-era bum Dan McGinty is recruited by the city's political machine to help with vote fraud. His great aptitude for this brings rapid promotion from "the boss," who finally decides he'd be ideal as a new, nominally "reform" mayor; but this candidacy requires marriage. His in-name-only marriage to honest Catherine proves the beginning of the end for dishonest Dan...

Women (Shirley Jones, Stella Stevens) and his mother help an English constable (James Booth) rise to ruler of a banana republic.

Banana Split takes the viewer on a journey that begins with the hustle and bustle of a fruit market in Thunder Bay, and ends up with an examination of the daily challenges of life in Honduras. In addition to being a popular fruit in Canada, bananas are used as a staple food in more than 100 tropical and sub-tropical countries.