The children in the film are the generation of Germans who became Nazis. Michael Haneke has stated that while that is intentional, the ideas in the film are meant to apply not just to fascism but to any form of radicalism, including terrorism. For this reason, the film's subtitle, "Eine Deutsche Kindergeschichte ("A German children's-story") is written in a unique German script and left untranslated, so that German audiences will regard the film as specifically about the roots of Nazism while audiences elsewhere can regard the themes as universal.
Michael Haneke wanted the environments to be very dark, so many indoor scenes used only practical light sources such as oil lamps and candles. In some of the darkest scenes, where the crew had been forced to add artificial lighting, extra shadows could be removed in the digital post-production which allowed for extensive retouching.
More than 7000 children were interviewed during the six-month-long casting period. For most of the adult roles, Michael Haneke selected actors with whom he had worked before and therefore knew they were suitable for the roles.
The production searched all of Northern Germany for a manor and surrounding buildings to use as their main shooting location, and found only one that had neither been destroyed nor modernized, and was not so dilapidated as to be unusable. They then restored it to the state it would have been in at the time the film took place.
Michael Haneke wrote the part of the Midwife for Susanne Lothar, after having worked with her on Funny Games (1997). He then had to talk her into playing the part, which she at first found too shocking.