When Maureen Coyle, a suicidal nun who resembles Norman's former victim, Marion Crane, arrives at the motel, all bets are off and "Mother" is less than happy.
Unfortunately the movie Psycho III is not yet available on Disney Plus.
| Directing | Anthony Perkins | Director |
| Writing | Charles Edward Pogue | Screenplay |
| Production | Hilton A. Green | Producer |
| Sound | Carter Burwell | Original Music Composer |
| Camera | Bruce Surtees | Director of Photography |
| Editing | David E. Blewitt | Editor |
| Production | Nancy Nayor | Casting |
| Art | Henry Bumstead | Production Design |
| Art | Mickey S. Michaels | Set Decoration |
| Costume & Make-Up | Peter V. Saldutti | Costume Design |
| Costume & Make-Up | Marla Schlom | Costume Design |
| Costume & Make-Up | Vivian McAteer | Hairstylist |
| Costume & Make-Up | Mark Reedall | Makeup Artist |
| Crew | Michael Westmore | Makeup Effects |
| Sound | Jeffrey Wilhoit | Foley |
| Sound | Michael C. Casper | Sound Re-Recording Mixer |
| Sound | Roger Heman Jr. | Sound Re-Recording Mixer |
| Sound | John J. Stephens | Sound Re-Recording Mixer |
| Sound | John Stacy | Supervising Sound Editor |
| Crew | Louis R. Cooper | Special Effects |
| Crew | Danny Lester | Special Effects |
| Crew | Karl G. Miller | Special Effects |
| Crew | Bob Yerkes | Stunt Coordinator |
| Visual Effects | Syd Dutton | Visual Effects |
| Camera | Rick Neff | Camera Operator |
| Camera | Christine M. Loss | Still Photographer |
| Camera | Michael Dugan | Underwater Camera |
| Costume & Make-Up | Brian O'Dowd | Set Costumer |
| Costume & Make-Up | Liza Stewart | Set Costumer |
| Directing | Betty A. Griffin | Script Supervisor |
| Production | Booker McClay | Publicist |
| Writing | Robert Bloch | Original Story |
| Production | Don Zepfel | Associate Producer |
| Sound | James Thompson | Sound Recordist |
