Paul Hubschmid
John McLaren
Madeleine Fischer
Katy Dandridge
Fiorella Mari
Mary McLaren
Ivo Garrani
Professor Herbert Weisse
Dario Michaelis
Peter Leduq
Jean-Jacques Delbo
Sergei Boetnikov
Peter Meersman
General van Dorff (uncredited)
Massimo Zeppieri
Dennis McLaren (uncredited)
Annie Bernal
Lab Assistant (uncredited)
Giacomo Rossi Stuart
Stuart (uncredited)
Gérard Landry
Landowsky (uncredited)
Shane Rimmer
John McLaren (uncredited) (voice)