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