The film is a sex-farce which follows the misadventures of a naïve young Melbourne man Alvin Purple, whom women find irresistible. Working in door to door sales, Alvin (unsuccessfully) tries to resist legions of women who want him.
Alvin is so worn-out he seeks psychiatric help to solve his problems. His psychiatrist is, of course, a woman. Alvin ultimately falls in love with the one girl who doesn't throw herself at him. She becomes a nun, and Alvin ends up a gardener in the convent's gardens.