It has an area of 3,551 sq km with a population of 270,000 inhabitants, of whom 250,000 are Catholic. It comprises 21 parishes served by 15 diocesan priests and 41 religious, has a seminary, 6 male religious communities and 25 female ones (*Ann. Pont.*, 1952, p. 317).
The diocese was created by Pope Pius XII with the apostolic constitution *Pastoralis, qua urgemur* of 13 April 1946, by separating territory from the dioceses of Niterói and Barra do Pirai, and raising to the rank and dignity of a cathedral the church dedicated to St Peter of Alcantara existing in Petrópolis. The first bishop was the present Mons. E. P. Da Cunha Cintra. The diocese is a suffragan of St Sebastian of Rio de Janeiro.
BIBL.: AAS, 39 (1947), pp. 77-86; G. B. Lehmann, *O Brasil Católico 1917*, Juiz de Fora 1947, p. 288.