Rock Hudson as Dr. Bartholomew Snow

Claudia Cardinale as Vicky Vicenti

Jack Warden as General George Pratt

Guy Stockwell as James Fitzpatrick

Anne Seymour as Miss Smith ("Smitty")

Alejandro Rey as Arthur Vincenti

Brad Dexter as Harrigan

Vito Scotti as Michelangelo Vincenti

Ted Knight as Dr. Bob Berford

Angela Clarke as Lavinia Vincenti

John Megna as Mario Vincenti

Ned Glass as Lippy

Hari Rhodes as Davis

Mort Mills as Henchman

Jack De Mave as Henchman

Chuck Roberson as Fitzpatrick's Henchman

Paul Comi as Barker

Morgan Jones as FBI Agent Mr. Nelson