In 1881 Algeria, an American soldier and a French aristocrat are about to have a duel over a woman when a comet hurtling past the Earth draws them into its gravitational pull. The men find themselves transported to the moon, where they discover a prehistoric civilization inhabited by reptiles and humans.

Based on the controversial off-Broadway musical comedy revue, "Oh! Calcutta!" is a series of musical numbers about sex and sexual mores. Most of the skits feature one or more performers in a state of undress, simulating sex, or both. The show sparked considerable controversy at the time because it featured extended scenes of total nudity, both male and female. The title is taken from a painting by Clovis Trouille, itself a pun on "O quel cul t'as!" French for "What an arse you have!".

Set in Palm Springs during a long, fun-filled weekend where several Los Angeles college students flock to spring break, centering on Jim who finds romance with Bunny, the daughter of Palm Springs harred, stressful police chief. Jim's bumbling roommate, Biff, tries to get Amanda, a tomboyish girl's attention with a so-called love gadget. Meanwhile, Gayle Lewis is a high school senior posing as a wealthy college girl who is pursued by Eric Dean, a wealthy and spoiled college prepie, while Gayle has eyes for a cowboy from Texas, named Stretch. Also Jim and Biff's basketball coach, Campbell, tries to romance Naomi, the owner of the motel where all of the gang is staying at, which is interfered by Naomi's young, trouble-making, brat son who's dubbed, Boom-Boom.