Balthazar was an untrained donkey during most of the filming, which made Bressons's work a real challenge. The only scene for which the donkey was trained was the circus math trick.
The main actress of this movie, Anne Wiazemsky, also became an author; in her book "Jeune Fille", she describes the making of the movie.
The soundtrack for the DVD release was copied at 24-bit from the original 35mm optical soundtrack print.