Assignment: Earth

William Shatner

James T. Kirk

Leonard Nimoy

Spock

DeForest Kelley

Dr. McCoy

James Doohan

Scott

Walter Koenig

Pavel Chekov

George Takei

Sulu

Nichelle Nichols

Uhura

Teri Garr

Roberta Lincoln

Eddie Paskey

Lieutenant Leslie (uncredited)

Robert Lansing

Gary Seven

Don Keefer

Cromwell

Barbara Babcock

Beta Five Computer (voice) / Isis (voice)

Frank da Vinci

Clifford Brent

April Tatro

Isis - human form

Edwin Rochelle

Man With Newspaper (uncredited)

Esther Ying Lee

Pedestrian (uncredited)

Bob Johnson

Ground Control (voice) (uncredited)

Rudy Doucette

Staff Member (uncredited)

Robert D'Arcy

Pedestrian (uncredited)

Bill Blackburn

Lieutenant Hadley / Rocket Base Technician (uncredited)

Paul Baxley

Security Chief

Ted Gehring

Second Policeman

Bruce Mars

First Policeman

Morgan Jones

Colonel Nesvig

Lincoln Demyan

Sergeant