 | Harold Lloyd als Harold Bledsoe |
 | Barbara Kent als Billie Lee |
 | Noah Young als Patrick Clancy SFPD |
 | Charles Middleton als John Thorne / The Dragon |
 | Will Walling als Captain Walton, SFPD 3rd Div. |
 | Grady Sutton als Man at Party (silent version) (scenes deleted) |
 | Brooks Benedict als Handcuffed Prisoner at Police Station (uncredited) |
 | Eddy Chandler als Cop (uncredited) |
 | Rae Daggett als Woman Sitting in Police Station (uncredited) |
| Douglas Haig als Buddy Lee (uncredited) |
 | Edgar Kennedy als SFPD Desk Sergeant (uncredited) |
 | Tetsu Komai als Florist Henchman (uncredited) |
 | James B. Leong als Florist Henchman / High Priest (uncredited) |
 | James Pier Mason als Barry Steele / Dick the Dude (uncredited) |
 | Nelson McDowell als 1st Train Passenger (uncredited) |
| James Wang als Dr. Chang Gow (uncredited) |
 | Blue Washington als Thorne's Henchman (uncredited) |
 | Leo Willis als Cop (uncredited) |
| Clyde Bruckman | Director |
| Malcolm St. Clair | Director |
| Paul Gerard Smith | Dialogue |
| Felix Adler | Story |
| Clyde Bruckman | Story |
| Harold Lloyd | Writer |
| Harold Lloyd | Producer |
| Bernard W. Burton | Editor |
| Carl Himm | Editor |
| Liell K. Vedder | Art Direction |
| John L. Murphy | Production Manager |
| Gaylord Lloyd | Assistant Director |
| Lodge Cunningham | Sound |
| George D. Ellis | Sound |
| C. Bakaleinikoff | Music Arranger |
| James H. Anderson | Production Assistant |
| Walter Lundin | Director of Photography |
| Henry N. Kohler | Director of Photography |
