The scene in which Sean Penn and Elizabeth McGovern go swimming in the lake was shot in the middle of winter which meant the water would also be freezing cold, but Penn and McGovern were so into the film they elected to do it anyway.
The shots in which Sean Penn and Nicolas Cage stand in on the railroad tracks with the train coming toward them were done with a large mirror positioned on the track, the camera shooting into it rather than the oncoming locomotive, to give the illusion that the train is actually coming toward them when the train is actually on a set of tracks nearby.
According to the September 1984 edition of Photoplay (UK) magazine, Sean Penn and Elizabeth McGovern had an "...intimate relationship off-screen during the making of the film. At one time they were living together, but they...split up".
Richard Benjamin once said of this movie: "The film is about the loss of innocence of three friends. The three leading characters have one foot in adulthood. It is that passionate, intense confused time before becoming adults, a time when everything burns brighter in youth - even in wartime".
Michael Madsen's missing lower right leg from the war was created by putting a hole in the hospital bed, putting the leg through it, and covering the thigh with bandage to create the illusion of a lost leg from the war.
The concept for this picture grew out of discussions between writer Steve Kloves and producer Alain Bernheim, the latter of whom was "interested in making a film about the war and its effects on the young".
Director Richard Benjamin tried to use Vaughn Monroe's signature tune "Racing With the Moon" (1941), fitting of the era, but the song did not fit well with the context of the end of the movie, and the use of it was scrapped.
The bowling alley where Sean Penn and Nicolas Cage work in the film was mostly built from scratch by production designers David L. Snyder and Jeannine Oppewall because the town in which the film was shot did not have one that fit that era. The hand-worked pin-strip bowling-ball mechanism, according to Richard Benjamin's audio-commentary, was an authentic piece of apparatus, and was found especially for the film, as they didn't make them anymore, all bowling pin retrievers having been replaced by mechanization.
The film's "Racing with the Moon" title was very similar to the earlier movie "The Raging Moon" [Long Ago, Tomorrow (1971)] whose title was derived from a phrase in a Dylan Thomas poem. The likeness ends there with the title, as the stories of both movies are completely different, except for romantic themes.