Writer and Director Tim Blake Nelson made Dr. Miklos Nyiszli's memoirs "Auschwitz: A Doctor's Eyewitness Account" (1946) mandatory reading for the film's cast, along with Primo Levi's "The Drowned and the Saved" (1986) and Filip Müller's "Eyewitness Auschwitz" (1979).
The actual plans of the Auschwitz-Birkenau extermination camp and its crematoria were used to build the sets as historically accurate as possible. A 90 % scale reproduction of Auschwitz-Birkenau's crematoria II and III (in the film, counted as I and II) was built near the village of Giten, 45 minutes outside Sofia, Bulgaria. The result represents a fairly accurate depiction of a small part of the Auschwitz-Birkenau extermination camp.
Expert Andreas Kilian criticized the depiction of the Sonderkommando revolt in The Grey Zone (2001) as "exaggerated" in his 2014 article "Zum 70. Jahrestag eines Symbols des Widerstands". Earlier depictions of the revolt in the films La passagère (1963) and Le triomphe de l'esprit (1989) would be misleading, too, because f.e. the Sonderkommando prisoners had no guns and grenades to defend themselves, there was no explosion in a crematory, only a fire, and only one crematory was damaged. The cinematic depiction in Le fils de Saul (2015) is the most accurate yet.