John Armstrong
— Steve Armstrong (voice)
Clifford Harrington
— Mark Gordon / Commander Robinson / Narrator / Additional Voices (voice)
Richard Murphy
— Big Bert Armstrong (voice)
Nancy Culluci
— Little John / Additional Voices (voice)
Gerri Sorrells
— Jamie Robinson (voice)
William Ross
— Dr Smith / Draco / Additional Voices (voice)
Don Johnson
— Dr Ned Armstrong (voice)
Judith Sackheim
— Dr Mary Ann Armstrong (voice)
Joseph Zucatti
— Dr Hook / Additional Voices (voice)
Greg Starr
— General Watson / Additional Voices (voice)
Richard Murphy
— Zambajil (voice)
Tom Clark
— Prince Zardoz (voice)
Patricia Kobiyashi
— Zandra (voice)
Mike Worman
— Zuhl (voice)
Avi Landau
— Additional Voices (voice)