The production company used thousands of American soldiers as extras. They were posted at nearby military facilities in Orleans, France. This movie was shot in the Loire Valley in France.
The movie was filmed in black-and-white at director Ralph Thomas' insistence. He explained his choice by saying the movie is based on a novel written in black-and-white.
Dirk Bogarde had to decline the role of Gaston played by Louis Jourdan in "Gigi" (1958) because he was already committed to this film.