The word Rambo means violence in Japanese.

After deciding to perform one of the stunts himself, Stallone broke a rib, much to the displeasure of director Ted Kotcheff. The shot however remained in the film. (The last sequence where Rambo falls through the trees.)

In the introduction to the 1988 Hodder Headline edition of the novel First Blood, author David Morrell says that he got the name Rambo from both a variety of apple, and the writer Rimbaud: "A French author's name and the name of an apple collided, and I recognized the sound of force."

Originally there was an alternate ending shot for the film in which Rambo killed himself, however, this was found too depressing and the script was changed for him to survive.