Full Credits
40 members

Hugh Marlowe
Dr. Russell A. Marvin

Joan Taylor
Carol Marvin

Donald Curtis
Maj. Huglin

Morris Ankrum
Brig. Gen. John Hanley

Thomas Browne Henry
Vice Adm. Enright

Grandon Rhodes
Gen. Edmunds

John Zaremba
Prof. Kanter

Paul Frees
Alien (voice)

Frank Wilcox
Alfred Cassidy
Sydney Mason
Frank the garage man

Larry J. Blake
Motorcycle cop
Bert Stevens
Air Intelligence Command Officer

Forbes Murray
Military Officer at Experiment

Arthur Tovey
Officer/Civilian at Military Conference
Alan Wells
Major Kimberly
Nicky Blair
Military Officer at Experiment (uncredited)
Jimmy Cross
Military Messenger (uncredited)
Jack Deery
Military Officer (uncredited)

Charles Evans
Dr. Alberts (uncredited)
Raoul Freeman
Military Official (uncredited)

Paul Frees
Alien (voice) (uncredited)
James Gonzalez
Military Official (uncredited)
Duke Green
Minor Role (uncredited)
Ed Haskett
Military Official (uncredited)

Clark Howat
Sgt. Nash (uncredited)

Harry Lauter
Cutting - Generator Technician (uncredited)
Don Marlowe
Minor Role (uncredited)
William Meader
Worker in Control Tower (uncredited)

Sol Murgi
Plane Passenger (uncredited)

Forbes Murray
Military Officer at Experiment (uncredited)
William J. O'Brien
Radio Listener (archive footage) (uncredited)
Murray Pollack
Plane Passenger (uncredited)

Mike Ragan
Tank Commander (uncredited)
Alan Reynolds
Maj. Kimberly (uncredited)

Dale Van Sickel
Man Crushed Beneath Wall (uncredited)
Guy Way
Civilian Observing Saucer Attack (uncredited)
Bob Whitney
Plane Passenger (uncredited)

Frank Wilcox
Alfred Cassidy (uncredited)
Beal Wong
Chinese Radio Listener (uncredited)

William Woodson
Narrator (voice) (uncredited)
17 members
Fred F. Sears
Director
Gene Anderson Jr.
Assistant Director
Donald E. Keyhoe
Novel
Curt Siodmak
Screenstory
George Worthing Yates
Screenplay
Bernard Gordon
Screenplay
Jack Erickson
Production Coordinator
Leon Chooluck
Unit Manager
Charles H. Schneer
Producer
Sam Katzman
Executive Producer
Fred Jackman Jr.
Director of Photography
J.S. Westmoreland
Sound
Paul Palmentola
Art Direction
Sidney Clifford
Set Decoration
Ray Harryhausen
Visual Effects
Danny B. Landres
Editor
Russ Kelley
Special Effects