Ben Mankiewicz on TCM indicated that Ivan Jandl spoke no English at the time this film was made, and that his English dialogue was phonetically memorized.
The first U.S. movie to be shot in a ravaged Germany after the end of WWII.
A total of seven languages are spoken and/or sung in this movie: English, German, French, Polish, Czech, Hungarian, and Hebrew. No subtitles are used for any of the dialogue.
Fred Zinnemann and Montgomery Clift toured UN Relief Camps to see what kind of trauma the children they would be depicting had gone through. Viewing German film shot in real concentration camps inevitably made the sensitive Clift vomit.
Clint Eastwood has singled out Montgomery Clift's performance in this film as one of the biggest influences on him as an actor.