William Powell as Philo Vance

Florence Eldridge as Sibella Greene

Ullrich Haupt as Dr. Von Blon

Jean Arthur as Ada Greene

Eugene Pallette as Sergeant Heath

E.H. Calvert as John F. X. Markham

Gertrude Norman as Mrs. Tobias Greene

Lowell Drew as Chester Greene

Morgan Farley as Rex Greene

Brandon Hurst as Sproot

Augusta Burmeister as Mrs. Mannheim

Marcia Harris as Hemming

Veda Buckland as Nurse (uncredited)

Shep Camp as Medical Examiner (uncredited)

Charles E. Evans as Lawyer Canon (uncredited)

Helena Phillips Evans as Miss O'Brien (uncredited)

Mildred Golden as Barton (uncredited)

Harry Strang as Policeman (uncredited)