Trivia: The security guard who gives "mother" a blanket at the end of the movie has the door opened for him by a young Ted Knight.
Trivia: When Detective Arbogast gets attacked by Norman's mother and falls backwards down the stairs, the actor, Martin Balsam, was actually just tap-dancing in front of a blue/green screen.
Suggested correction: This is partially correct. The actor is in front of a screen projecting the image of the stairs behind him, not blue or green screened onto the image. In addition, according to at least one analysis going into detail of the making of the film, he was sitting on a slanted chair, so he was convincingly horizontal and flailing his arms only, not "tap dancing."
Trivia: The sound of the knife stabbing Marion's flesh in the shower scene was made by stabbing a melon.
Trivia: A body-double was used in the shower scene when anything else besides Janet Leigh's face, neck, shoulders, and arms are seen on screen.
Trivia: Director Hitchcock hid the model of Mother in Janet Leigh's bedroom and listened to how loudly she screamed when she saw it to test its effectiveness.
Trivia: Walt Disney hated the film so much that he refused to allow Alfred Hitchcock to film at Disneyland for another film he directed.