This was one of Audrey Hepburn's favorite of her films. It was also one of her most financially successful.
The role of Sister Luke was suggested for Ingrid Bergman but Bergman herself said she was too old for the role and instead proposed Audrey Hepburn.
An often-reported legend surrounding this movie is the story that Audrey Hepburn demanded a bidet be provided for her on location in the Congo. Hepburn always denied this, wondering how such an extravagance could even be hooked up in the Congo.
Audrey Hepburn met the real Marie-Louise Habets - inspiration for the novel and film - while she was preparing for the role. The two actually became great friends and Habets later nursed Hepburn back to health after her near-fatal horse-riding accident on the set of The Unforgiven (1960).
The opening credits play out over street scenes of Bruges (or Brugge in Dutch). At over 1,500 years old (though did not receive its city charter until 1128), it is one of the oldest cities in Belgium, and was at one time the most important commercial city in the world.