 | David Hemmings als Marcus Daly |
 | Daria Nicolodi als Gianna Brezzi |
 | Gabriele Lavia als Carlo |
 | Macha Méril als Helga Ulmann |
 | Eros Pagni als Supt. Calcabrini |
 | Giuliana Calandra als Amanda Righetti |
 | Piero Mazzinghi als Bardi |
 | Glauco Mauri als Prof. Giordani |
 | Clara Calamai als Marta |
 | Aldo Bonamano als Carlo's Father |
| Liana Del Balzo als Elvira |
 | Vittorio Fanfoni als Cop Taking Notes |
 | Dante Fioretti als Police Photographer |
 | Geraldine Hooper als Massimo Ricci |
| Jacopo Mariani als Young Carlo |
 | Furio Meniconi als Rodi |
 | Fulvio Mingozzi als Agent Mingozzi |
 | Lorenzo Piani als Fingerprint Cop |
 | Salvatore Puntillo als Police Agent |
 | Piero Vida als Fat Cop |
 | Nicoletta Elmi als Olga |
 | Dario Argento als Murderer's Hands (uncredited) |
| Salvatore Baccaro als Fruit Vendor (uncredited) |
 | Omero Capanna als Hitman (uncredited) |
 | Bruno Di Luia als Concerned Man in Restroom (uncredited) |
 | Attilio Dottesio als Florist (uncredited) |
 | Tom Felleghy als Surgeon (uncredited) |
 | Glauco Onorato als (uncredited) |
 | Marilù Tolo als Carol (archive footage) (uncredited) |
| Franco Vaccaro als Pietro Valgoi (uncredited) |
| Gianni Di Segni als Rabbi (uncredited) |
 | Marc Smith als Professor Giordani (voice) |
 | Mario Pascucci als Library Caretaker (uncredited) |
| Bernardino Zapponi | Screenplay |
| Dario Argento | Writer |
| Dario Argento | Director |
| Giorgio Gaslini | Original Music Composer |
| Franco Fraticelli | Editor |
| Stefano Rolla | Assistant Director |
| Elena Mannini | Costume Design |
| Luigi Kuveiller | Director of Photography |
| Salvatore Argento | Producer |
| Claudio Argento | Executive Producer |
| Armando Mannini | Set Decoration |
| Angelo Iacono | Production Manager |
| Angela Viglino | Seamstress |
| Francesco Bellomo | Still Photographer |
| Ubaldo Terzano | Camera Operator |
| Germano Natali | Special Effects |
| Vivalda Vigorelli | Continuity |
| Nicla Palombi | Hairstylist |
| Giovanni Morosi | Makeup Artist |
| Giuliano Laurenti | Makeup Supervisor |
| Mario Faraoni | Sound Recordist |
| Eugenio Fiori | Boom Operator |
| Nick Alexander | Sound Editor |
| Sergio Coletta | Gaffer |
| Carlo Rambaldi | Special Effects |
| Antonio Tonti | Assistant Camera |
| Maurizio Garrone | Assistant Art Director |
| Antonio Annunziata | Assistant Camera |
| Giuseppe Bassan | Production Design |
| Massimo Anzellotti | Foley Artist |
| Sergio Emidi | Key Grip |
| Carlo Du Bois | Production Accountant |
| Cesare Jacolucci | Production Coordinator |
| Carlo De Marchis | Special Effects Assistant |
| Aldo Taloni | Construction Foreman |
| Stefano Olivieri | Set Dresser |
| Carlo Cucchi | Assistant Production Manager |
| Piero Bozza | Assistant Editor |
| Claudio Simonetti | Original Music Composer |
