After finishing primary school in Târgu Ocna, Cristescu attended the Veniamin Theological Seminary in Iași, graduating in 1916. That year he enrolled at the Law Faculty of the University of Iași, but interrupted his studies due to World War I. He took part in the autumn 1916 campaign with the rank of "sergent TR" (reduced term sergeant) in the sanitary service. He continued his university studies after the war ended, and received the title of doctor in legal sciences six years after graduating.