Eastern Catholic churches maintain the ancient Eastern discipline of allowing married men to be ordained to the diaconate and priesthood. A man who is married before ordination may serve as a priest; however, men may not marry after ordination. Bishops, by ancient tradition, are chosen from among celibate monks rather than married clergy. This discipline coexists within Catholic communion and is explicitly protected by the Code of Canons of the Eastern Churches.

The Eastern Catholic tradition recognizes the same threefold order of ministry as the Latin Church: deacon, priest (presbyter), and bishop. Priests celebrate the Divine Liturgy, administer the sacraments, and provide pastoral care. The ordained priesthood is understood to share in the one priesthood of Christ, and the laity also participate in the royal priesthood of the faithful.