Howard Duff
— Dave Pomeroy
Linda Cristal
— Dr. Paula Stevens
Stephen McNally
— James Kincade
Nehemiah Persoff
— August Best
Anne Jeffreys
— Myra Pryor
Oscar Beregi Jr.
— Dr. Paul Cerbo
Gregory Morton
— Steadman
Dennis Hopper
— Goff
George Barrows
— Ernest
John Hoyt
— Dr. Milton Becker
Steve Franken
— Hal Johnson
Mike Farrell
— Dick Blaine
Stanley Clements
— Albert
Rush Williams
— Reporter
Eilene Janssen
— Information Clerk
Wesley Lau
— Lt. Brady
George Sawaya
— Karl Sinden (Mr. X)