John Armstrong

as Steve Armstrong (voice)

Clifford Harrington

as Mark Gordon / Commander Robinson / Narrator / Additional Voices (voice)

Richard Murphy

as Big Bert Armstrong (voice)

Nancy Culluci

as Little John / Additional Voices (voice)

Gerri Sorrells

as Jamie Robinson (voice)

William Ross

as Dr Smith / Draco / Additional Voices (voice)

Don Johnson

as Dr Ned Armstrong (voice)

Judith Sackheim

as Dr Mary Ann Armstrong (voice)

Joseph Zucatti

as Dr Hook / Additional Voices (voice)

Greg Starr

as General Watson / Additional Voices (voice)

Richard Murphy

as Zambajil (voice)

Tom Clark

as Prince Zardoz (voice)

Patricia Kobiyashi

as Zandra (voice)

Mike Worman

as Zuhl (voice)

Avi Landau

as Additional Voices (voice)