Frank Hardy
Frank Buck
Tiger Van Dorn
Sasha Siemel
Robert Banning
Richard Tucker
Armand Roget
Duncan Renaldo
John Charles
Fred Kohler Jr.
Paul Marshall
Sherwood Bailey
Campbell
Harry 'Snub' Pollard
Professor
George Rosener
Mrs. Maitland
Gertrude Sutton
Chandler Elliott
John St. Polis
Doctor Coleman
John Davidson
Singapore Joe
Milburn Morante
Ralph Marshall
Reginald Denny
Joe Nolan
Dirk Thane
Angus MacLeod
Robert Warwick
Hardy's Assistant
Dahlam Ali
Henchman
Jim Corey
Greenway
Paul Ellis
Jackson
Henry Hale
Roget Clerk #1
Harry Harvey
Sailor
Reed Howes
Undercover Detective at Dive
Jack Ingram
Detective Interrogating Pete
Tom London
Valerie Shields
Esther Ralston
Peters
Merrill McCormick
Blackie Whiteford
Roger Williams
Dorothy Elliott
Charlotte Henry
Tom Banning
William Bakewell
Lightning
Clarence Muse
Chiang-Houseboy
Willie Fung
Jim Murphy
LeRoy Mason
Inspector Starrett
Matthew Betz
Screenplay
Gordon Griffith
Stunts
George Magrill
Director
George Melford
Harry L. Fraser
Eddie Parker
Harry O. Hoyt
Sherman L. Lowe
George M. Merrick
Arthur Hoerl
Dallas M. Fitzgerald
Editor
Earl Turner
Carl Mathews
Producer
Louis Weiss
Director of Photography
Edward Linden
Sound
Corson Jowett
Original Music Composer
Lee Zahler
Herman Schopp
T.T. Triplett