In 1435, Pope Eugene IV named him apostolic prothonotary [5][8] and in 1443 appointed Barbaro as Bishop of Treviso.
[4][5][9] In 1447, the Pope promised Barbaro the nomination as Bishop of Bergamo, but instead appointed Polidoro Foscari to the position.
Barbaro left Rome and traveled Italy, but he returned to work in the curia and remained there until 1453.
Nicholas V appointed him Bishop of Verona and Barbaro settled there on a permanent basis,[4][5][10] except for a brief period in Perugia, from 1460 to 1462, as governor.
[4][5] In 1460, he was sent as a papal legate to Charles VII of France[4][5] Barbaro was responsible for the construction of the Bishop’s Palace at Monteforte d'Alpone between 1453–1471, designed by Michele da Caravaggio.