Muki Betser was born in 1945 in his grandparents' house in moshav Nahalal. They were among the seven people (along with Moshe Dayan's father) who established Israel's first kibbutz, Degania.^[6] His mother, Sarah Hurvitz, was born and raised in Tel Aviv; her family lived in the area for five generations.^[7] His father, Nahman Betser, was born in the second kibbutz in Israel, Merhavia, that his grandparents also helped establish.^[8] Betser lived in Nahalal until he was four, then moved with his family to Haifa, where his father worked as a major construction contractor.^[9][10] His family's return to the Jezreel Valley to live in Beit She'arim when he was eight, was one of the "happiest days" of his life.^[11][12]

Betser married in February 1967. They lived in the house that his wife Nurit inherited in Nahalal, the childhood home of Moshe Dayan, only a few houses away from where Betser was born. They had one son, Saul, who followed Betser into "The Unit". Nurit died when she was 29.^[13] Betser remarried in 1982, and had two daughters, Tamar and Shani.^[14]

Betser established a pre-military program in the kibbutz Maagan Michael, considered one of the best in Israel.