Robert Beatty
— Dr. Mark Benton
Elizabeth Sellars
— Della Freeman
Peter Coke
— Det. Insp. George Bellamy
Hugh Kelly
— Dr. Craig
Vida Hope
— Jackie Leroy
Janet Butler
— Sister Rogers
Ferdy Mayne
— Charles Constance
James Raglan
— Supt. Grayson
Hugh Pryse
— Mr. Rattray
George Benson
— Prescott
Roger Delgado
— Felix Galegos
Frank Atkinson
— Railway Ticket Clerk (uncredited)
Donald Conlon
— Helios Restaurant Patron (uncredited)
Arthur Dibbs
— Helios Restaurant Patron (uncredited)
Robert Gregory
— Man at Northolt Airport (uncredited)
Jean Hardwicke
— Sister (uncredited)
Barry Johns
— Hospital Orderly (uncredited)
Anthony Lang
— Johnny (uncredited)
Ronald Leigh-Hunt
— Sgt. Lewis (uncredited)
Richard Neller
— Hospital Visitor (uncredited)
Harold Sanderson
— Hospital Visitor (uncredited)
Marc Sheldon
— Waiter (uncredited)
Toke Townley
— Fred Barker (uncredited)