George Murphy
Inspector James 'Jim' Belden
Finlay Currie
Professor Albert Kafer
Virginia Gilmore
Millie / Teresa Zalenko
Karl Stepanek
Alexi Laschenkov / Gregory Anders
Louisa Horton
Mrs. Elaine Wilben
Peter Capell
Chris Zalenko / Gino
Bruno Wick
Luther Danzig
Vilma Kurer
Mrs. Rita Foss
Ann Thomas
Philadelphia Suspect
George Roy Hill
Nicholas Wilben
Karl Weber
FBI Agent Charlie Reynolds
Michael Garrett
Michael Dorndoff aka Frank Torrance
Lotte Palfi Andor
Anna Kafer
Ernest Graves
Robert Martin
Robert Carroll
Boldany
Wolfgang Zilzer
August Helmuth
Bradford Hatton
Harry Mason
Rosemary Pettit
Mrs. Martin
Eva Condon
Landlady
Steve Mitchell
Samson
John Farrell
Taxi Driver (uncredited)
Nancy Hale
Mrs. Belden (uncredited)
Westbrook Van Voorhis
Narrator (voice) (uncredited)
Mary Young
Old Lady (uncredited)
Suzanne Moulton
Sherry Belden (uncredited)
Louis Applebaum
Original Music Composer
Leo Rosten
Story
Alfred L. Werker
Director
Leo Rosten
Screenplay
Louis De Rochemont
Producer
Angelo Ross
Editor
Joseph C. Brun
Director of Photography
Herbert Andrews
Art Direction
George Stoetzel
Camera Operator
Lothar Wolff
Associate Producer
Thomas Whitesell
Unit Manager
Jack Shaindlin
Music Director
Lodge Cunningham
Sound
Shirlee Weingarten
Casting Director
Peter Ratkevich
Assistant Editor
Borden Mace
Associate Producer
Edward Horton
Camera Operator
Laurence Heath
Additional Writing
Emmett Murphy
Additional Writing
Virginia Shaler
Additional Writing