Guri Weinberg played his own father. He is the son of Moshe Weinberg, the Israeli wrestling referee and former champion, who died in the massacre when Guri was just one month old.
Avner is referred to as a "sabra" more than once. This is an Israeli term for a child born in Israel to immigrant parents. "Sabra" originally referred to a tough kind of cactus (Opuntia cactus) which grew out in the desert.
The film was not shot in Munich or Germany at all. The Munich scenes were mostly shot in Budapest, Hungary.
During the scene where Avner's (Eric Bana's) team joins up with the Israeli commandos in Beirut, one of the commandos introduces himself as Ehud Barak. Barak was a member of the most elite commando force of the Israeli army, Sayeret Matkal, before becoming a politician and eventually Israel's Prime Minister.
Actor and director Mathieu Kassovitz had left strict instructions to his agent that he would not take any acting assignments at all, as he wanted to fully concentrate on directing features. However, this film was an exception. According to him, he accepted the role of Robert because he jumped at the chance to work with Steven Spielberg.
Steven Spielberg: [father] Avner's father is in jail, Avner himself is away from his wife and newborn child during the first year or so of her life.