Trivia

Many of the actors who played the Nazis were in fact European Jews who had fled Nazi occupation.

During the scene in which the "La Marseillaise" is sung over the German song "Die Wacht am Rhein" ("The Watch on the Rhine"), many of the extras had real tears in their eyes as a large number were actual refugees from Nazi persecution in Germany and elsewhere in Europe and were overcome by the emotions the scene brought out. The scene was inspired by Jean Renoir's The Grand Illusion (1937), in which French soldiers in a German POW camp sing the song as a similar gesture of defiance. Marcel Dalio, who played Emil the croupier, had also appeared in The Grand Illusion (as Lieutenant Rosenthal). "La Marseillaise" was written in 1792 by Claude Joseph Rouget de Lisle in Strasbourg after the declaration of war by France against Austria and was originally titled "Chant de guerre pour l'Armée du Rhin" ("War Song for the Rhine Army").

Rick's Cafe was one of the few original sets built for the film, the rest were all recycled from other Warner Bros. productions due to wartime restrictions on building supplies.

Because the film was made during WWII the production was not allowed to film at an airport after dark for security reasons. Instead, it used a sound stage with a small cardboard cutout airplane and forced perspective. To give the illusion that the plane was full-sized, they used little people to portray the crew preparing the plane for take-off. Years later the same technique was used in Alien (1979), in the scene where the crew discovers the dead "space jockey," with director Ridley Scott's son and some of his friends in scaled-down spacesuits.

It is never revealed why Rick cannot return to America. Julius J. Epstein later said that "my brother (Julius J. Epstein) and I tried very hard to come up with a reason why Rick couldn't return to America. But nothing seemed right. We finally decided not to give a reason at all."