 | Ira von Fürstenberg als Trudy Farrell |
 | Edwige Fenech als Marie Chaney |
 | Howard Ross als Jack Davidson |
 | Helena Ronee als Peggy Davidson |
 | Teodoro Corrà als George Stark |
 | Ely Galleani als Isabel |
 | Edith Meloni als Jill Stark |
 | Mauro Bosco als Charles |
 | Maurice Poli als Nick Chaney |
 | William Berger als Prof. Gerry Farrell |
| Mario Bava | Editor |
| Antonio Rinaldi | Director of Photography |
| Luigi Alessi | Producer |
| Mario Bava | Director |
| Mario Di Nardo | Screenplay |
| Roberto Ranucci | Assistant Costume Designer |
| Orietta Melaranci | Makeup Artist |
| Emilio Varriano | Camera Operator |
| Armando Pietrangeli | Still Photographer |
| Giulia Mafai | Costume Design |
| Ira von Fürstenberg | Executive Producer |
| Pietro Bregni | Producer |
| Mario Bregni | Producer |
| Mario Bava | Director of Photography |
| Mario Di Nardo | Story |
| Mario Bava | Additional Writing |
| Piero Umiliani | Original Music Composer |
| Agatha Christie | Novel |
| Adolfo Martello | Assistant Production Manager |
| Mario Bianchi | Assistant Director |
| Giulia Mafai | Set Dresser |
| Giuseppe Aldrovandi | Production Design |
| Alfonso Cucci | Assistant Production Manager |
| Giulia Mafai | Set Decoration |
| Leopoldo Rosi | Sound |
| Luigi Alessi | Production Manager |
