 Stephen ForsythJohn Harrington | John Harrington |
 Dagmar LassanderHelen Wood | Helen Wood |
 Laura BettiMildred Harrington | Mildred Harrington |
 Jesús PuenteInspector Russell (as Jesus Puente) | Inspector Russell (as Jesus Puente) |
 Femi BenussiAlice Norton | Alice Norton |
| AAntonia MasLouise | Louise |
 Luciano PigozziVences (as Alan Collin) | Vences (as Alan Collin) |
 Gérard TichyDr. Kalleway (as Gerard Tichy) | Dr. Kalleway (as Gerard Tichy) |
 Verónica LlimeráBetsy Wester (as Veronica Llimera) | Betsy Wester (as Veronica Llimera) |
| PPasquale FortunatoJohn Harrington as a Boy (as Fortunato Pascuale) | John Harrington as a Boy (as Fortunato Pascuale) |
 Ignasi AbadalJimmy Kane (as José Ignacio Abadaz) | Jimmy Kane (as José Ignacio Abadaz) |
| SSilvia LienasVicky | Vicky |
| MMontserrat Riba VidalRosy Miller (as Monserrat Riba) | Rosy Miller (as Monserrat Riba) |
 Susy AndersenSdenka (archive footage) (uncredited) | Sdenka (archive footage) (uncredited) |
| GGuido BarlocciUnknown (uncredited) | Unknown (uncredited) |
| BBruno BoschettiPoliceman (uncredited) | Policeman (uncredited) |
| EElina De WittModel (uncredited) | Model (uncredited) |
 Rika DialynaMaria (archive footage) (uncredited) | Maria (archive footage) (uncredited) |
 Boris KarloffGorca (archive footage) | Gorca (archive footage) |
 Glauco OnoratoGiorgio (archive footage) (uncredited) | Giorgio (archive footage) (uncredited) |
