At age five, he and his family moved to the Weissensee district where he attended primary school and was the target of antisemitism from classmates.

[6] As a person of partial Jewish ancestry (a Mischling in Nazi terminology), Beck was not deported with other German Jews.

[6] He recalls in his autobiography borrowing a neighbor's Hitler Youth uniform[7] and marching in 1942[8] into the pre-deportation camp where his lover, Manfred Lewin, had been arrested and detained.

[10] Gad Beck joined an underground effort to supply food and hiding places to Jews escaping to neutral Switzerland.

[6] His parents and sister did survive the war, thanks to help from their Christian relatives on his mother's side.

[9][13] Also in 2000, the English translation of Beck's 1995 autobiography, An Underground Life: Memoirs of a Gay Jew in Nazi Berlin, was published, leading to a successful book tour through the United States.