 | Tony Musante als Sam Dalmas |
 | Suzy Kendall als Julia |
 | Enrico Maria Salerno als Inspector Morosini |
 | Eva Renzi als Monica Ranieri |
 | Umberto Raho als Alberto Ranieri |
 | Renato Romano als Professor Carlo Dover |
 | Giuseppe Castellano als Monti |
 | Mario Adorf als Berto Consalvi |
 | Pino Patti als Faiena |
 | Gildo Di Marco als Garullo |
 | Rosita Torosh als Victim |
 | Omar Bonaro als Police Detective |
 | Fulvio Mingozzi als Police Detective |
 | Werner Peters als Antique Dealer |
 | Karen Valenti als Tina |
 | Carla Mancini als Girl Watching TV |
| Bruno Erba als Police Detective |
| Annamaria Spogli als Sandra Roversi (uncredited) |
 | Giovanni Di Benedetto als Professor Rinaldi (uncredited) |
 | Reggie Nalder als Needles (uncredited) |
 | Maria Tedeschi als Old Lady in Fog (uncredited) |
 | Aldo Barozzi als Passerby who calls the Police (uncredited) |
| Ugo Mari als Mario Zandri (uncredited) |
| Dario Argento | Director |
| Ennio Morricone | Original Music Composer |
| Vittorio Storaro | Director of Photography |
| Dario Micheli | Costume Design |
| Salvatore Argento | Producer |
| Lidia Puglia | Hairstylist |
| Alberto Bartolomei | Sound Mixer |
| Dario Micheli | Production Design |
| Fredric Brown | Novel |
| Giuseppe Ferranti | Makeup Artist |
| Franco Fraticelli | Editor |
| Camillo Teti | Production Manager |
| Carlo Diotallevi | Sound |
| Dario Argento | Story |
| Dario Argento | Screenplay |
| Artur Brauner | Producer |
| Roberto Pariante | First Assistant Director |
| Umberto Sambuco | Unit Manager |
| Enrico Umetelli | Camera Operator |
| Arturo Zavattini | Camera Operator |
| Cesarina Casini | Assistant Editor |
| Sergio Fraticelli | Assistant Editor |
| Lida Chitarrini | Script Supervisor |
| Eugenio Fiori | Boom Operator |
| Angelo Tavazza | Administration |
| Bruno Nicolai | Conductor |
| Luciano Anzellotti | Foley Artist |
