George C. Scott

Dan Charles Logan

Richard Basehart

Dr. Roy Caldwell

Martin Sheen

Maj. Holliford

Barnard Hughes

Dr. Spencer

Nicolas Beauvy

Chris Logan

Paul Stevens

Col. William Franklin

Stephen Young

Major Reintz

Kenneth Tobey

Col. Alan A. Nickerson

Robert Walden

Dr. Janeway

William Jordan

Major Cooper

Dabbs Greer

Dr. Thompson

John Dierkes

Bill Parker

Bette Henritze

Sarah Parker

Lou Frizzell

Dr. Spike Boynton

Ed Lauter

Simpson

Phoebe Noel

Waitress

Steve DeFrance

Ambulance Driver (uncredited)

Anna Aries

Bit Part

Fielding Greaves

Dr. Walter Steenrod, Chivington Research Laboratories

Terry Wilson

Kaufman Trucking Co. driver