Filmography
| Role | Title | Year | Character |
|---|---|---|---|
| Writer | Psyco | 1960 | |
| Writer | Psycho | 1998 | |
| Writer | Psycho IV | 1990 | |
| Writer | Un giorno da ricordare | 1995 | |
| Actor | Going to Pieces: The Rise and Fall of the Slasher Film | 2006 | Himself |
| Writer | Il terrore negli occhi del gatto | 1969 | |
| Writer | Orchidea nera | 1958 | |
| Writer | The Kindred | 1987 | |
| Writer | Il dubbio | 1961 |