Young Dr. Kildare

Lionel Barrymore Dr. Leonard Gillespie

Lew Ayres Dr. James Kildare

Lynne Carver Alice Raymond

Nat Pendleton Joe Wayman

Jo Ann Sayers Barbara Chanler

Samuel S. Hinds Dr. Stephen Kildare

Emma Dunn Mrs. Martha Kildare

Walter Kingsford Dr. P. Walter Carew

Truman Bradley Jack Hamilton

Monty Woolley Dr. Lane-Porteus

Pierre Watkin Mr. Robert Chanler

Nella Walker Mrs. Chanler

Murray Alper Blue Swan Waiter (uncredited)

Don 'Red' Barry Dr. Collins (uncredited)

Granville Bates Harry Cook (uncredited)

Barbara Bedford Nurse (uncredited)

Margaret Bert Little Boy's Mother (uncredited)

Marie Blake Miss Sally Green (uncredited)

Virginia Brissac Boardinghouse Landlady (uncredited)

John Butler Coronary Patient (uncredited)