Mansour Hobeika studied philosophy and theology at Saint Joseph University in Beirut from 1962 to 1968.
Ordained to the priesthood on June 9, 1968, he studied canon law at the Instituto per l'Oriente Carlo Alfonso Nallino in Rome and in the Angelicum, obtained his doctorate in Oriental Canon law in Rome.
He taught at the Université La Sagesse, graduating himself from a course in Islamic studies and Arabic language.
Hobeika was appointed bishop of the Maronite Eparchy of Zahleh, Lebanon, on September 12, 2002, by Pope John Paul II and was ordained bishop on October 26, 2002, by the hands of Maronite Patriarch of Antioch, Cardinal Nasrallah Boutros Sfeir.
His co-consecrators were Roland Aboujaoudé, auxiliary bishop of Antioch and Chucrallah Harb, Emeritus Eparch of Jounieh.