Francesco Matrone, known as "the Beast," was on the interior ministry's list of nine most dangerous fugitives, the Italian news agency ANSA reported.
He was due to serve two life sentences for a double homicide when he went on the run five years ago.
Matrone, 65, is a member of the Camorra crime organization and head of the Matrone crime family.
Police did not say where Matrone was arrested.
In 2004, he escaped custody but was located a short time later, hiding out with the owner of a dog kennel.