Phoenix secretary Marion Crane (Janet Leigh), on the lam after stealing $40,000 from her employer in order to run away with her boyfriend, Sam Loomis (John Gavin), is overcome by exhaustion during a heavy rainstorm. Traveling on the back roads to avoid the police, she stops for the night at the ramshackle Bates Motel and meets the polite but highly strung proprietor Norman Bates (Anthony Perkins), a young man with an interest in taxidermy and a difficult relationship with his mother.

A wheelchair-bound photographer spies on his neighbors from his Greenwich Village courtyard apartment window and, despite the skepticism of his fashion-model girlfriend, becomes convinced one of them has committed murder.