Isaac Peeper was  a son of Meijer Jesaias Peeper and Marianne Halverstad. He married in Amsterdam on 10 Juni 1903 Betje Roos, a daughter of Nathan Roos and Engeltje Plukker. The couple had four children, of whom one daughter has survived the Holocaust. The other children, Meijer, Nathan and Marianne were killed in the Shoah.

Isaac Peeper was born into a family with six children. He had five other sisters of whom one has died in 1929. His other sisters Alida, Debora, Judith and Rachel have been killed in the Shoah.

City Archive of Amsterdam, archive cards of  Isaac Peeper, Debora Peeper  Rachel Peeper, Judith Peeper en website www.wiewaswie.nl.