Audrey Hepburn
Sister Luke

Peter Finch
Dr. Fortunati

Edith Evans
Rev. Mother Emmanuel

Peggy Ashcroft
Mother Mathilde

Dean Jagger
Dr. Hubert Van Der Mal

Mildred Dunnock
Sister Margharita

Beatrice Straight
Mother Christophe

Patricia Collinge
Sister William

Rosalie Crutchley
Sister Eleanor

Ruth White
Mother Marcella

Barbara O'Neil
Mother Didyma

Margaret Phillips
Sister Pauline

Colleen Dewhurst
Dangerous Hospital Patient

Lionel Jeffries
Dr. Goovaerts

Niall MacGinnis
Father Vermeuhlen

Eva Kotthaus
Sister Marie

Dorothy Alison
Sister Aurelie

Jeanette Sterke
Louise

Errol John
Illunga

Orlando Martins
Kalulu

Penelope Horner
Jeanette Milonet (uncredited)

Ave Ninchi
Sister Bernard (uncredited)

Richard O'Sullivan
Pierre (uncredited)

Elsa Albani
(uncredited)

Gabriella Andreini
(uncredited)

Giovanna Galletti
(uncredited)