Eastern Catholic churches accept the primacy of the Bishop of Rome (the Pope) as a defined doctrine of the Catholic Church, while exercising genuine self-governance through their own patriarchs, major archbishops, and synods of bishops. This model of conciliarity—collegial episcopal governance—is an essential feature of Eastern ecclesiology.

The Code of Canons of the Eastern Churches (CCEO, 1990) governs Eastern Catholics and protects their rights to maintain their own liturgical, theological, and disciplinary traditions. Eastern Catholic theology is sensitive to the balance between Petrine primacy and the ancient tradition of conciliarity: unity is expressed through communion with Rome, while the administration, liturgy, and spiritual life of each church is managed by its own hierarchy. This is sometimes described as 'diversity in unity.'