 Stewart GrangerDavid Porter | David Porter |
 Lex BarkerGlenn Cassidy | Glenn Cassidy |
 Pierre BriceAgent Brice | Agent Brice |
 Karin DorDenise (Rio segment) | Denise (Rio segment) |
 Walter GillerKarl (Vienna segment) | Karl (Vienna segment) |
 Johanna MatzMonique Carrar (Vienna segment) | Monique Carrar (Vienna segment) |
 Klaus KinskiGomez (Rio segment) | Gomez (Rio segment) |
 Richard MünchProfessor Alden (Frame story) | Professor Alden (Frame story) |
 Peter VogelWendt, Suspected girls' killer (Frame story) | Wendt, Suspected girls' killer (Frame story) |
 Pascale PetitLotty (Vienna segment) | Lotty (Vienna segment) |
 Agnès SpaakNelly Small (Rio segment) | Nelly Small (Rio segment) |
 Herbert FuxThug #2 (Vienna segment) (uncredited) | Thug #2 (Vienna segment) (uncredited) |
 Harald DietlHans, Thug #1 (Vienna segment) (uncredited) | Hans, Thug #1 (Vienna segment) (uncredited) |
 Raoul RetzerDoorman (Vienna segment) (uncredited) | Doorman (Vienna segment) (uncredited) |
 Margaret LeeAgent Linda (Rome segment) | Agent Linda (Rome segment) |
| RRoberto MialiPessana (Rio segment) | Pessana (Rio segment) |
 Carla CalòFemale boss (Rome segment) | Female boss (Rome segment) |
 Carmen G. CerveraJoana (Rio segment) | Joana (Rio segment) |
| AAllen PinsonRay Runner (Rio segment) | Ray Runner (Rio segment) |
 FregolenteHarry Brenton (Rio segment) | Harry Brenton (Rio segment) |
| KKim CambaGigi (Rome segment) (unconfirmed) | Gigi (Rome segment) (unconfirmed) |
 Fortunato ArenaTaxi driver (Rome segment) (uncredited) | Taxi driver (Rome segment) (uncredited) |
 Alberto BonucciProfessor (Rome segment) (uncredited) | Professor (Rome segment) (uncredited) |
 Pietro CeccarelliGangster #2 (Rome segment) (uncredited) | Gangster #2 (Rome segment) (uncredited) |
 Spartaco ConversiGangster #4 (Rome segment) (uncredited) | Gangster #4 (Rome segment) (uncredited) |
 Franco DaddiGangster #3 (Rome segment) (uncredited) | Gangster #3 (Rome segment) (uncredited) |
 Robert FavartSergej (Vienna segment) (uncredited) | Sergej (Vienna segment) (uncredited) |
 Michael JanischKurt Waldeck (Vienna segment) (uncredited) | Kurt Waldeck (Vienna segment) (uncredited) |
 José LewgoyPresident (Rio segment) (uncredited) | President (Rio segment) (uncredited) |
 Luciano PigozziIvan (Rome segment) (uncredited) | Ivan (Rome segment) (uncredited) |
