text: After completing the script for the film, Eichinger presented it to director Oliver Hirschbiegel. Though he was interested in exploring how the people of Germany "could have plumbed such depths", as a German, Hirschbiegel hesitated to take it as he "reacted to the idea of Nazism as a taboo". Hirschbiegel eventually agreed to helm the project.
  Casting
  When Bruno Ganz was offered the role of Hitler, he was reluctant to accept the part, and many of his friends advised against it, but he believed that the subject had "a fascinating side", and ultimately agreed to take the role.
  Ganz conducted four months of research and studied a recording of Hitler in private conversation with Finnish Field Marshal Carl Gustaf Emil Mannerheim in order to properly mimic Hitler's conversational voice and Austrian dialect. Ganz came to the conclusion that Hitler had Parkinson's disease, noting his observation of Hitler's shaky body movements present in the newsreel Die Deutsche Wochenschau, and decided to visit a hospital to study patients with the disease. Ganz auditioned in the casting studio with makeup for half an hour and tested his voice for Hirschbiegel who was convinced by his performance.
  Alexandra Maria Lara was cast as Traudl Junge; she was given Junge's book Until the Final Hour (2002), which she called her "personal treasure", to read during filming. Before she was cast, she had seen André Heller's documentary film Im toten Winkel which impressed her and influenced her perspective on Junge.