After his release, Leopold moved to Puerto Rico where, in 1961, he married Trudi Feldman Garcia de Queveda, a widowed social worker from Baltimore. Her first husband had been a Puerto Rican doctor.
On August 19, 1971, Leopold died of heart problems, related to diabetes. When he died, his wife was at his at his side.
He had maintained all the requirements of his parole. He died without any known backsliding.