Lew Ayres as Dr. James Kildare

Lionel Barrymore as Dr. Leonard Gillespie

Laraine Day as Nurse Mary Lamont

Samuel S. Hinds as Dr. Stephen Kildare

Gene Lockhart as George Winslow

John Shelton as Dr. Davidson

Nat Pendleton as Joe Wayman

Emma Dunn as Mrs. Martha Kildare

Alma Kruger as Molly Byrd

Walter Kingsford as Dr. Walter Carew

Nell Craig as Nurse Parker

Cliff Danielson as Dr. Jordan

Henry Wadsworth as Collins

Tom Collins as Joiner

George H. Reed as Conover

Donald Briggs as Mr. Brownlee

Leona Maricle as Mrs. Brownlee

Archie Twitchell as Bates

Marie Blake as Sally

Charles Trowbridge as Atkinson

Arthur O'Connell as Intern (uncredited)

Eddie Acuff as Clifford Genet - an Orderly (uncredited)

Erville Alderson as Boylston - City Council Member (uncredited)

Arthur Aylesworth as Mr. Cobb - a Farmer (uncredited)

Barbara Bedford as Carew's Secretary (uncredited)

Jack Carr as Dr. Marsh (uncredited)

Mary Cecil as Mrs. Deering (uncredited)

George Chandler as Parkersville Counterman (uncredited)

Ken Christy as Dickson - City Council Member (uncredited)

Jane Drummond as Nurse Probationer (uncredited)

Ralph Dunn as Motorcycle Cop (uncredited)

Bob Ingersoll as Carpenter Adding Sign on Door (uncredited)

Claire McDowell as Nurse for Mr. Winslow (uncredited)

Horace McMahon as Foghorn Murphy (uncredited)

Frank Orth as Mike Ryan (uncredited)

Milton Parsons as Parkersville Crazy Man (uncredited)

Ruth Robinson as Mother of Baby (uncredited)

Ferris Taylor as Dr. Coldridge (uncredited)

Kay Vallon as Nurse Shaw (uncredited)