Director John Moore was nearly killed in the scene where the tank busts through the wall. He was pulled away by a stuntman just in time.
Owen Wilson separated his shoulder doing stunt work on the movie. He was back the next day shooting action sequences.
The film is based loosely on the experiences of U.S. Air Force Captain Scott O'Grady, who was shot down over Bosnia in June 1995, and was stranded in Serb-held territory for six days before being rescued by U.S. Marines. O'Grady brought a lawsuit against Twentieth Century Fox for damages to his character. He claims he didn't curse as much and never disobeyed orders. The suit was eventually settled out of court.
None of the actors playing Serbians were actually Serbian; the producers said that they hired Croats as interns and instructors to teach the actors the Serbian language (which is virtually identical to Croatian), because they couldn't find any Serbs willing to work on the film due to perceived anti-Serb sentiment shown in the film. Vladimir Mashkov, who played the Serbian sniper Sasha, is Russian, and Olek Krupa, who played the Serbian General Miroslav Lokar, is Polish. Some Slovaks also participated in the film, such as Marko Igonda, who played Colonel Bazda, and Kamil Kollarik, who played a guerrilla who aids Burnett in Hac.
The production made all of the snow out of paper. At the time of filming, it was the first winter in one hundred four years that it hadn't snowed in Slovakia.