Leo Gorcey
— Terence Aloysius 'Slip' Mahoney
Huntz Hall
— Horace Debussy 'Sach' Jones
Betty Compson
— Selena Webster
Gabriel Dell
— Gabe
Teala Loring
— Eleanor Williams
William Benedict
— Whitey
Bobby Jordan
— Bobby
David Gorcey
— Chuck
Bernard Gorcey
— Louie
Dan Seymour
— Dr. Armand
Byron Foulger
— Prof. Quizard
Patti Brill
— Alice
Pierre Watkin
— Dr. Rolfe Carter
Danny Beck
— Lennie the Meatball
Carmen D'Antonio
— Receptionist
Noble Johnson
— Hasson / Richard
William Ruhl
— McGregor - Apartment Manager
Louis Faust
— Tom Williams (uncredited)