Elroy Jetson invents a time machine that takes him back to prehistoric times, where he meets the Flintstone family.
Mel Blanc
as Barney Rubble / Dino / Mr. Spacely (voice)
Daws Butler
as Elroy Jetson / W.C. Cogswell / Henry Orbit (voice)
Don Messick
as Astro / R.U.D.I / Mac / Announcer / Store Manager / Robot (voice)
Henry Corden
as Fred Flintstone / Knight (voice)
Jon Bauman
as Iggy (voice)
Hamilton Camp
as Turk Tarpit (voice)
Julie McWhirter
as Betty Rubble / Jet Rivers / Investor / Panelist / Harem Girl (as Julie Dees) (voice)
George O'Hanlon
as George Jetson (voice)
Penny Singleton
as Jane Jetson (voice)
John Stephenson
as Mr. Slate / Moderator / Investor / Poker Player (voice)
Brenda Vaccaro
as Didi (voice)
Jean Vander Pyl
as Wilma Flintstone / Rosie / Mrs. Spacely (voice)
