 Anthony FranciosaPeter Neal | Peter Neal |
 John SaxonBullmer | Bullmer |
 Daria NicolodiAnne | Anne |
 Giuliano GemmaDetective Germani | Detective Germani |
 Christian BorromeoGianni | Gianni |
 Mirella D'AngeloTilde | Tilde |
 Veronica LarioJane McKerrow | Jane McKerrow |
 Ania PieroniElsa Manni | Elsa Manni |
 Eva Robin'sGirl on Beach | Girl on Beach |
 Carola StagnaroDetective Altieri | Detective Altieri |
 John SteinerChristiano Berti | Christiano Berti |
 Lara WendelMaria Alboretto | Maria Alboretto |
| IIsabella AmadeoBullmer's secretary | Bullmer's secretary |
 Mirella BantiMarion | Marion |
 Ennio GirolamiDepartment Store Manager | Department Store Manager |
| MMonica MaisaniNot listed | Not listed |
 Marino MaséJohn | John |
 Fulvio MingozziAlboretto | Alboretto |
 Giampaolo SaccarolaCoroner | Coroner |
 Ippolita SantarelliProstitute | Prostitute |
 Francesca ViscardiNot listed | Not listed |
 Dario ArgentoNarrator / Murderer's Hands (voice) (uncredited) | Narrator / Murderer's Hands (voice) (uncredited) |
 Lamberto BavaElevator Repairman #1 (uncredited) | Elevator Repairman #1 (uncredited) |
 Michele SoaviMaria's Boyfriend / Man with Girl on Beach (uncredited) | Maria's Boyfriend / Man with Girl on Beach (uncredited) |
| CChristina LindbergensenScreaming woman (uncredited) | Screaming woman (uncredited) |
 Dolores CalòTraveller at the airport (uncredited) | Traveller at the airport (uncredited) |
