While the concentration camp is never mentioned by name, Auschwitz was the only Nazi death camp with four crematoria. The SS officers are discussing the building's construction in the Commandant's office when Bruno's mother interrupts the meeting. In the book, Bruno calls it "Out-With."
Bruno's parents are named Ralf and Elsa, but in the credits of the film they are listed as "Father" and "Mother." This is a tribute to the novel, in which the narrative focuses solely on Bruno's point of view.
Rupert Friend initially turned down the role as Lieutenant Kotler because he was shocked by the violent nature of his character. He said, "I mean, it's not particularly flattering to be associated with a group of people who attempted to exterminate an entire race. I'm not a shouty person, and I'm not violent either. The character scared me. But then I realized that that was probably the point. It was about putting a human face on these atrocities." However, Friend struggled throughout filming and became withdrawn after shooting the more harrowing scenes.
Some parts in the movie is of some parts of the story of Rudolph Höss, a two-time commander in Auschwitz. The name "Ralf" is a play with names. His wife did not want him "in bed" after realizing what they where doing in the camp (whereupon he was unfaithful with the maid). The house in which the film was made looks remarkably like their house close to Auschwitz. The children became aware of the camp. His rank (Lieutenant Colonel) is same that Höss had at the time. In real life, however, Höss had four children and, of course, what happened in the movie did not happen to the Höss family.
Given a closer look during the scene when Bruno and his friends run past a truck being loaded with arrested Jews, a little boy is seen being lifted up by his father. This is strongly implied to be Shumel, as the boy strongly resembles him.
The trivia item below may give away important plot points.
In regard to shooting the final scene, director Mark Herman remarked, "It was a nightmare on many levels. We probably had more lawyers than filmmakers. We had all of the legalities of kids in amongst grown-up naked people."