Norman Bates is still running his little motel, and he has kept the dressed skeleton he calls mother. One of his guests is a young girl who has left the convent where she lived. To get some help he employs a young man. One day a nosey journalist comes to see him to ask questions about his past.
| Director Anthony Perkins, originally wanted Jeff Fahey to be completely nude in the foreplay scene between Duke and Red, but Jeff Fahey felt too uncomfortable with being completely nude on camera, so he was allowed to hold two lamps to partially cover himself. |
| Anthony Perkins's directorial debut. |
| Anthony Perkins originally suggested Psycho III be filmed in black and white but Universal opposed it. |
| Mary's book from Psycho II (1983) (called "In the Belly of the Beast") is seen laying in the dirt, by Norman's house. |
| The original script had Duane as the killer emulating Norman Bates's crimes. |
| Universal had planned the release of Psycho III for 14 February 1986. |
| After completion, Universal felt the film needed a better ending with more of a twist, so Perkins was called back to shoot the final scene. |
| Stuntman Kurt Paul played "Mother", except for when we actually see Anthony Perkins dressed up as "Mother" at the end. This is why we never get to see Mother's face on screen. Mother's face is always blacked out, or hidden in the shadow's. |
