An attractive young woman (star Marilyn Chambers's first appearance in the world of sin) is kidnapped from a roadside bar in an ordinary town in the United States. After being taken to a mysterious cabaret hidden behind a green door, she is semi-hypnotized and her body becomes the protagonist of an erotic spectacle before an audience hiding their faces behind masks.
In 1972, Marilyn Chambers saw an ad in the San Francisco Chronicle for a casting call for what was billed as a "great movie." She rushed to the audition, but discovered it was for a pornographic film to be called "Behind the Green Door." She was about to leave when producers Artie and Jim Mitchell noticed her resemblance to Cybill Shepherd and invited her up to their offices to tell her the film's plot. Chambers was very hesitant about accepting a role in a pornographic film, fearing it might ruin her chances of breaking into the advertising world. But the fantasy of the story appealed to her, and she decided to take a chance, on the condition that she would receive a substantial salary and a percentage of the film's takings.