Robert Hutton as Tom Gregory

Robert Burton as Prof. Galbraith

Susan Hart as Lisa Galbraith

Judee Morton as Bonnie Galbraith

William Boyce as Cal Johnson

Les Tremayne as Norman Tolliver

John Close as KTTV Reporter Vince Williams

Edward Finch Abrams as Bum in Theater (uncredited)

Bob Herron as Slime Person (uncredited)

Jock Putnam as Slime Person (uncredited)

Tracy J. Putnam as Dr. Timothy Brough (uncredited)

Blair Robertson as Mrs. Castillo (uncredited)

Fred Stromsoe as Slime Person (uncredited)