As the movie reached a large audience, it caused the real "child of Buchenwald", Stefan Jerzy Zweig, who survived the camp as a four-year-old, and was now living in Tel Aviv, to become aware of the novel and the film based on his experience. He came to East Germany and studied Camera at the film academy in Babelsberg.
Bruno Apitz was inspired by the story of the child's survival to work his own experiences in Buchenwald (where he was a prisoner from 1937 - 1945) into a movie script. When his expose was turned down by the DEFA he decided to write a novel instead. The novel was enormously successful (it sold 2 million copies and was translated into many languages), prompting the DEFA to reconsider.
Wolfgang Lagerhoff, himself a former concentration camp prisoner, was first asked to direct the movie, but he could not find the time. It was then offered to Frank Beyer, who had already done two historic and unique war movies (Fünf Patronenhülsen (1960), Royal Children (1962)).
Frank Beyer went to great effort to convince the famous theatre actor Ernst Busch to take on his first big movie role (as Walter Kraemer). After a long struggle, Erst Busch accepted, but two weeks prior to filming suffered a heart attack, which left him unable to act for several months. Thus Erwin Geschonneck, who had spent time in a camp as well, was cast instead.
Prior to the film, East German TV had already produced and broadcast a TV production of the same title. Director Frank Beyer adopted three of the actors that had already appeared in the TV film (Fred Delmare, Wolfram Handel, and Peter Sturm).