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The enemy helicopter that Rambo eventually destroys is an Aerospatiale Puma mocked up to resemble a Soviet Mi-24 Hind gunship. The helicopter was one of three originally modified for use in Red Dawn (1984). For that film it had a modified front end that resembled the Soviet helicopter even more closely. However this modification blocked the pilot's view and adversely affected the helicopter's aerodynamics, so it was removed. Rambo battles the same helicopter again in Rambo III (1988).
To prepare for this role, Sylvester Stallone did eight months of training for four hours a day. He also took SWAT combat, archery and survival courses.
The film is dedicated to special effects technician Cliff Wenger Jr., who was accidentally killed by one of the film's explosions.
Dolph Lundgren was initially signed as the Russian Lieutenant Colonel Podovsky (played by Steven Berkoff), when Sylvester Stallone realized that it was the same man who was going to be in Rocky IV (1985), so they paid off the contract.
At the time of filming (1985), there were close to 2,500 Vietnam veterans still missing in action.
Co-writer James Cameron claims that he only wrote the first draft of the script, and that Sylvester Stallone made many changes to it. Cameron had originally paired Rambo with a humorous sidekick, and had fleshed out the prisoners of war with elaborate backstories that were to be revealed over the course of the film. However, Stallone reportedly didn't like that the sidekick got all the cool dialogue, and also scrapped most of the POW's backstories to the point where Cameron claimed that "they might as well have gotten to the jungle to pick up a six-pack of beer". When the film was released, the political content of the movie was considered controversial, with many feeling that the Vietnam War was altered to look and sound heroic. Cameron commented that he only wrote the action, and that Stallone wrote the politics.