James Lee "Jimmy" Wong

Keye Luke

Win Lee, Benton's Secretary

Lotus Long

Police Captain Street

Grant Withers

Detective Grady

Paul McVey

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

Charles Miller

Dr. Norman Wilkes

Huntley Gordon

Louise Benton

Virginia Carpenter

Charlie Frasier

John Dilson

Mason

John Holland

Toreno

Richard Terry

Toreno

Jack Perrin

Tommy Dean

Robert Kellard

Jonas

William Castello

Jonas

Willy Castello

Foo

Lee Tung Foo

Radio News Broadcaster

Lynton Brent

Wilkes

Huntly Gordon

Stakeout Cop

Jack Cheatham

Detective in Refrigerator

Heinie Conklin

Policeman

William Gould

Police Officer Stationed at Front Door

Bruce Mitchell

Extra in Audience at Benton's Lecture

William J. O'Brien

Charley One

Victor Wong