Robert Livingston

Dr. Lawrence Baxter

Grace Bradley

Jean Sterling

Willard Robertson

Inspector 'Mac' McDonald

Pierre Watkin

Kennedy

Smiley Burnette

Jimmy

Granville Bates

Prof. Rexford Sterling

William Newell

Andrews

Byron Foulger

Pete Andorka

Wilbur Mack

F. J. Thompson

Matty Fain

Burke

Josephine Whittell

Nurse Nelson

Charles Timblin

Swain

Billy Griffith

Kellogg

William Hopper

Announcer

Frank Du Frane

Golden

Mary Russell

Nurse (uncredited)

Florence Gill

Spinster

Frank Austin

Henchman (uncredited)

Richard Beach

Henchman (uncredited)

Harrison Greene

Hospital Administrator (uncredited)

John Holland

Druggist (uncredited)

Monte Montague

Henchman (uncredited)

William H. O'Brien

Nightclub Waiter (uncredited)

Carleton Young

Radio Announcer (uncredited)