| Pour une poignée de dollars | 1964 | Screenplay |
| Le Retour de Ringo | 1965 | Screenplay |
| Sept écossais du Texas | 1966 | Screenplay |
| Kiss Kiss... Bang Bang | 1966 | Screenplay |
| Le temps du massacre | 1966 | Screenplay |
| Johnny Yuma | 1966 | Screenplay |
| Navajo Joe | 1966 | Screenplay |
| Les Longs Jours de la vengeance | 1967 | Screenplay |
| Les Sept écossais explosent | 1967 | Screenplay |
| Wanted | 1967 | Screenplay |
| Pécos tire ou meurt | 1967 | Screenplay |
| Omicidio per appuntamento | 1967 | Screenplay |
| Poker au Colt | 1967 | Writer |
| Odio per odio | 1967 | Writer |
| Con lui cavalca la morte | 1967 | Screenplay |
| Sugar Colt | 1967 | Screenplay |
| La lunga sfida | 1967 | Writer |
| Chacun pour soi | 1968 | Writer |
| ...E venne il tempo di uccidere | 1968 | Screenplay |
| Pas de pitié pour les salopards | 1968 | Screenplay |
| Rose rosse per il Führer | 1968 | Screenplay |
| Dieu les crée moi je les tue | 1968 | Screenplay |
| Gangsters '70 | 1968 | Writer |
| Pourquoi pas avec toi | 1969 | Writer |
| Amarsi male | 1969 | Writer |
| La Jeunesse du massacre | 1969 | Screenplay |
| La Clinique sanglante | 1971 | Screenplay |
| Milan Calibre 9 | 1972 | Screenplay |
| Passeport pour deux tueurs | 1972 | Screenplay |
| La seduzione | 1973 | Writer |
| Le Boss | 1973 | Screenplay |
| Salut Les Pourris | 1974 | Screenplay |
| Ursula l'anti-gang | 1975 | Screenplay |
| Colère noire | 1975 | Screenplay |
| Deux flics à abattre | 1976 | Screenplay |
| Les féroces | 1976 | Screenplay |
| Mister Scarface | 1976 | Screenplay |
| Diamanti sporchi di sangue | 1978 | Screenplay |
| Avoir vingt ans | 1978 | Screenplay |
| Vacanze per un massacro | 1980 | Screenplay |
| Razza violenta | 1984 | Screenplay |
| Killer contro killers | 1985 | Writer |
| Killer contro killers | 1985 | Screenplay |
