Cast
Richard Münch
Professor Alden (Frame story)
Margaret Lee
Agent Linda (Rome segment)
Robert Favart
Sergej (Vienna segment) (uncredited)
Herbert Fux
Thug #2 (Vienna segment) (uncredited)
Harald Dietl
Hans, Thug #1 (Vienna segment) (uncredited)
Raoul Retzer
Doorman (Vienna segment) (uncredited)
Stewart Granger
David Porter
Johanna Matz
Monique Carrar (Vienna segment)
Peter Vogel
Wendt, Suspected girls' killer (Frame story)
Pascale Petit
Lotty (Vienna segment)
Carla Calò
Female boss (Rome segment)
Klaus Kinski
Gomez (Rio segment)
Carmen G. Cervera
Joana (Rio segment)
Alberto Bonucci
Professor (Rome segment) (uncredited)
José Lewgoy
President (Rio segment) (uncredited)
Luciano Pigozzi
Ivan (Rome segment) (uncredited)
Lex Barker
Glenn Cassidy
Pietro Ceccarelli
Gangster #2 (Rome segment) (uncredited)
Spartaco Conversi
Gangster #4 (Rome segment) (uncredited)
Michael Janisch
Kurt Waldeck (Vienna segment) (uncredited)
Karin Dor
Denise (Rio segment)
Agnès Spaak
Nelly Small (Rio segment)
Pierre Brice
Agent Brice
Walter Giller
Karl (Vienna segment)
Fregolente
Harry Brenton (Rio segment)
Fortunato Arena
Taxi driver (Rome segment) (uncredited)
Franco Daddi
Gangster #3 (Rome segment) (uncredited)