Peter Cushing
Dr. Victor Stein
Francis Matthews
Dr. Hans Kleve
Eunice Gayson
Margaret Conrad
Michael Gwynn
Karl
John Welsh
Bergman
Lionel Jeffries
Fritz
Oscar Quitak
Dwarf
Richard Wordsworth
Up Patient
John Stuart
Inspector
Michael Ripper
Kurt
Charles Lloyd Pack
President
Arnold Diamond
Molke
M
Marjorie Gresley
Countess Barscynska
A
Anna Walmsley
Vera Barscynska
George Woodbridge
Janitor
Ian Whittaker
Boy
A
Avril Leslie
Girl
J
John Tatham
Manservant (uncredited)
E
Eugene Leahy
Kleine (uncredited)
C
Charles Gilliard
Policeman (uncredited)
J
Jimmy Charters
Patient (uncredited)
J
Julia Nelson
Inga (uncredited)
R
Robert Brooks Turner
Joseph the Groom (uncredited)