"What good are closed convents to the Church? They should serve the flesh of Christ and refugees are the flesh of Christ," he said at the Astalli Jesuit refugee center in downtown Rome.
"Empty convents don't help the Church by being turned into hotels to make money".
The visit marks his second to a center for asylum seekers after a much-acclaimed July trip - his first outside Rome as pope - to Lampedusa, the first point of arrival in Europe for many desperately fleeing their home countries.
Entering through the cafeteria of the center in Rome, the pope met with several refugees, most of whom were from Africa, among the tens of thousands who pass through the center annually.
"Thank you for defending your dignity, but also our human dignity," he said in a 20-minute speech that addressed tensions often felt between native Italian Catholics and refugees of diverse ethnic and religious backgrounds. "Many of you are Muslims or come from other religions.
You come from various countries.
We mustn't be afraid of differences.
Fraternity helps us discover they are treasures, a gift to all.
Let us live in fraternity".