Warren William as Perry Mason

Genevieve Tobin as Della Street

Patricia Ellis as Margie Florence Clune

Lyle Talbot as Dr. Robert Doray

Allen Jenkins as Spudsy Drake

Barton MacLane as Bisonette

Peggy Shannon as Thelma Bell

Porter Hall as Col. Bradbury

Anita Kerry as Eva Lamont

Craig Reynolds as Frank Patton

Henry O'Neill as District Attorney C. Manchester

Charles C. Wilson as Police Officer Ricker

Joseph Crehan as Detective Johnson

Olin Howland as Dr. Croker

Mary Treen as Spudsy's Wife

Joe Downing as George Sanborne (as Joseph Downing)