 | Vincent Price als Dr. Robert Morgan |
 | Franca Bettoia als Ruth Collins |
 | Emma Danieli als Virginia Morgan |
 | Giacomo Rossi Stuart als Ben Cortman |
 | Umberto Raho als Dr. Mercer |
 | Christi Courtland als Kathy Morgan |
| Antonio Corevi als Governor |
 | Ettore Ribotta als TV Reporter |
| Rolando De Rossi als TV Reporter |
 | Giuseppe Mattei als New People Leader |
| Enrico Salvatore als TV Reporter |
 | Alessandro Tedeschi als Passerby |
| Carolyn De Fonseca als Ruth Collins (voice) |
| Sidney Salkow | Director |
| Vico Vaccaro | Production Manager |
| Richard Matheson | Novel |
| Luciano Volpato | Production Supervisor |
| Ubaldo Ragona | Screenplay |
| Alfonso Avincola | Still Photographer |
| Robert L. Lippert | Producer |
| Bruno Zanoli | Boom Operator |
| Gene Ruggiero | Editor |
| Pierantonio Mecacci | Makeup Artist |
| Renato Pedrini | Electrician |
| Ubaldo Ragona | Director |
| Alvaro Lanzoni | Camera Operator |
| Franco Rispoli | Other |
| Rita Agostini | Script Supervisor |
| Ermete Santini | Other |
| Brunello Serena Ulloa | Set Decoration |
| Angiolina Menichelli | Costume Design |
| Norman B. Schwartz | Music Editor |
| Richard Matheson | Screenplay |
| Samuel Z. Arkoff | Executive Producer |
| Enzo Silvestri | Sound Engineer |
| Armando Timpani | Sound Recordist |
| Carmen Frosali | Costume Supervisor |
| Harold E. Knox | Associate Producer |
| Furio M. Monetti | Screenplay |
| William F. Leicester | Screenplay |
| Carlo Grandone | Assistant Director |
| Franco Delli Colli | Director of Photography |
| Bert Shefter | Original Music Composer |
| Paul Sawtell | Original Music Composer |
| Angelo Lannutti | Assistant Camera |
| Federico Tocci | Key Grip |
| Giorgio Giovannini | Art Direction |
| Lionello Meucci | Assistant Production Manager |
| Alfonso D'Artega | Orchestrator |
