Tony Britton
Dr. Robert Marriott
Virginia Maskell
Dr. Lucy Byrne
Ian Bannen
Alan Andrews
Kenneth Griffith
Dr Shole
Peter Cushing
Professor Sewell
Thorley Walters
Special Agent Prince
Donald Pleasence
Parsons, alias Bill Brown
Spike Milligan
Arthur, lab orderly
Raymond Huntley
Sir George Gatting the Minister of Defense
Sam Kydd
Slater