Filmography
| Role | Title | Year | Character |
|---|---|---|---|
| Writer | Superman | 1978 | |
| Writer | Superman II | 1980 | |
| Writer | Superman III | 1983 | |
| Writer | Gangster Story | 1967 | |
| Writer | Moonwalker | 1988 | |
| Writer | Superman II: The Richard Donner Cut | 2006 | |
| Writer | La vera storia di Babbo Natale | 1985 | |
| Writer | La vera storia di Babbo Natale | 1985 | |
| Writer | Ma papà ti manda sola? | 1972 | |
| Writer | Sheena regina della giungla | 1984 | |
| Writer | Una lama nel buio | 1982 | |
| Writer | Hackers 2 - Takedown | 2000 | |
| Actor | DeadTectives | 2018 | Lloyd |
| Writer | HIStory on Film, Volume II | 1997 | |
| Actor | Score: A Film Music Documentary | 2017 | Himself |
| Writer | It's a Bird, It's a Plane, It's Superman! | 1975 | |
| Writer | Uomini e cobra | 1970 | |
| Actor | T and T | Dick Decker | |
| Producer | 100 Bloody Acres | 2012 | |
| Producer | R.O.T.O.R. | 1987 | |
| Actor | Easy Riders, Raging Bulls: How the Sex, Drugs and Rock 'N' Roll Generation Saved Hollywood | 2003 | Himself |
| Writer | Cattive compagnie | 1972 | |
| Actor | Conversations on Alex North's Spartacus: The Celebration of a Masterpiece | 2010 | David Newman |