Keye Luke as James Lee Wong

Lotus Long as Win Lee, Benton's Secretary

Grant Withers as Police Captain Street

Charles Miller as Dr. John Benton / Cyrus Benton in Newspaper (as Charles Miller)

Huntley Gordon as Dr. Norman Wilkes

Virginia Carpenter as Louise Benton

John Dilson as Charlie Frasier

Paul McVey as Detective Grady

John Holland as Mason

Richard Terry as Toreno

Robert Kellard as Tommy Dean

Willy Castello as Jonas

Lee Tung Foo as Foo

Lynton Brent as Radio News Broadcaster

Jack Cheatham as Stakeout Cop

Heinie Conklin as Detective in Refrigerator

William Gould as Policeman

Bruce Mitchell as Police Officer Stationed at Front Door

William J. O'Brien as Extra in Audience at Benton's Lecture

Victor Wong as Charley Won