Leo Gorcey
— Terence Aloysius 'Slip' Mahoney
Huntz Hall
— Horace Debussy 'Sach' Jones
Lloyd Corrigan
— Edgar Alden Franklin Smith
Lela Bliss
— Margo
Philip Van Zandt
— Dr. Basil Granville
Bernard Gorcey
— Louie
William Benedict
— Whitey
Buddy Gorman
— Butch
David Gorcey
— Chuck
Jan Kayne
— Cynthia
Argentina Brunetti
— Mrs. Parelli
Marshall Bradford
— Professor Krantz
Robert Coogan
— Jack Eagan
Michael Ross
— Gus
Bess Flowers
— Seance Guest (uncredited)