Donald Sutherland
Matthew Bennell

Brooke Adams
Elizabeth Driscoll

Leonard Nimoy
Dr. David Kibner

Jeff Goldblum
Jack Bellicec

Veronica Cartwright
Nancy Bellicec

Art Hindle
Dr. Geoffrey Howell

Lelia Goldoni
Katherine Hendley

Kevin McCarthy
Running Man

Don Siegel
Taxi Driver

Tom Luddy
Ted Hendley

Stan Ritchie
Stan

Garry Goodrow
Dr. Boccardo

Jerry Walter
Restaurant Owner

Maurice Argent
Chef

Wood Moy
Mr. Tong

Joe Bellan
Harry

Al Nalbandian
Rodent Man

Robert Duvall
Priest on Swing (uncredited)

Michael Chapman
Health Dept. Floor Cleaner (uncredited)

Philip Kaufman
City Official on Phone (uncredited) (voice)