Lew Ayres

Dr. James Kildare

Lionel Barrymore

Dr. Leonard Gillespie

Laraine Day

Nurse Mary Lamont

Shepperd Strudwick

Dr. Gregory 'Greg' Lane

Samuel S. Hinds

Dr. Stephen Kildare

Emma Dunn

Mrs. Martha Kildare

Nat Pendleton

Joe Wayman, Ambulance Driver

Walter Kingsford

Dr. S.J. 'Walter' Carew, Hospital Administrator

Alma Kruger

Molly Byrd, Superintendant of Nurses

John Eldredge

Henry Adams, Amnesia Patient

Nell Craig

Nurse 'Nosey' Parker

Marie Blake

Sally, Hospital Switchboard Operator

Charles Waldron

Dr. 'Egghead' Squires, Messinger Inst.

George Lessey

Rufus Ingersoll

George H. Reed

Conover, Gillespie's Attendant

Paul Porcasi

Antonio 'Tony', the Hospital Chef

Horace McMahon

J. Harold 'Fog Horn' Murphy

Frank Orth

Mike Ryan, Sullivan's Hospital Cafe

Margaret Seddon

Mrs. Julia Cray, Skin Alergy Patient

Fay Helm

Mrs. Henry Adams

William Bailey

Spectator in Operating Theatre (uncredited)

Stephen Chase

Ambulance Interne (uncredited)

Donald Douglas

Mr. Grayson, Patient losing Eye Sight (uncredited)