During an audience for anti-crime activists the Holy Father urged the Mafia and other groups to stop their criminal activity and turn to God.
"Open your hearts to the Lord. The Lord is waiting for you and the Church will welcome you if your willingness to serve good is as clear and public as your choice to serve evil was," he said.
Last year on a visit to an area blighted by gangs the Pope said the organised crime groups were involved in the "adoration of evil".
Francis was also issuing the call to a group called 'Ndrangheta, which its claimed made more money last year than fast food chain McDonald's.
Most of its cash comes from drugs.