Continuity mistake: When Christine is fixing herself after the guys smashed her up, her front end is shown to be perfectly straight for its entire width and the hood is missing. Near the end of the scene, the front end is shown crushed and unfolds again, and the hood appears from nowhere.
Continuity mistake: Eddie drives a 1957 Chevy convertible off the bridge. A scene showing the car being fished out of the water clearly has an older vehicle dangling from the line.
Suggested correction: The car pulled onto the bridge is absolutely a 1957 Chevrolet convertible.
Continuity mistake: After Norman argues with Mr Toomey, before he goes up to the house, you can plainly see the light on in the living room where Mary is sitting. When Norman goes in the house, Mary is sitting in the dark and Norman then turns on the light.
Continuity mistake: Henrietta Dodd shoots Johnny holding the gun in her right hand. Sheriff Bannermann emerges from the bathroom and shoots Henrietta. The film switches to slow motion as she is shot and stretches both of her arms out to the sides as she falls. When she lands, her left hand is resting next to the railing of the stairs and is covered in blood. At no time did her hand come in contact with her wound or get any blood splattered onto it.
Continuity mistake: When Meg comes up to Angela, taunting her, Angela's head position and the look on her face changes in each shot.