The public toilets just off St Mark's square will include soap and towels.
The idea came to light after a meeting between Archbishop Konrad Krajewski and a man named Franco who lives on the streets.
Speaking to La Stampa's Vatican Insider website he said he met the man after confession: "I brought him with me anyway. We had Chines.
"While we were at the table, he told me that you can always find something to eat in Rome. But what is missing are places to wash yourself."
Archbishop Konrad, who's been described as an extension of Pope Francis, will oversee the work which begins later this month.
He's also encouraging other groups working with the homeless to provide shower facilities and says his office will help with the funding.
Acknowledging the difficulties that many homeless shelters face he said: "It is not simple.
"It is easier to prepare sandwiches than to run a shower service - you need volunteers, towels, clean underwear."