Pinczewski was born to parents Icek and Ruchla on 11 May 1930 in Wiskitki, east-central Poland. He had one sister.
Wiskitki was seized by the Germans on 8 September 1939. The 2,000 resident Jews were resettled to the Warsaw ghetto.
Pinczewski's Nazi records shows that he spent four years in the ghetto, and one year in concentration camps.