There are some Roman structures, the so-called Baths of Neptune, few meters from the famous Pesco Montano passage, very close to both the Port and via Appia, on the town boundaries. They are still visible on the ground floor of the Salvini’s Villa, partly reused in the Middle Ages as chapel and infirmary of a Leper hospital dedicated to St Mary Magdalene. The primary known reference concerning the leprosarium must be the mention in Odda Mancarella’s will (1236), where there’s no indication on the belonging of the hospital. Secondly, there’s evidence that the management of the leprosarium was in the care of a begging friars’ order, probably Franciscans. Moreover, in the mid 14th century the management appeared neither continuous nor uniform, but by turns, with administrators belonging to both the secular and the regular clergy; among these, in 1349 the Cistercians of Fossanova are highlighted as the first monastic order certainly linked to our leprosarium. In 1353 the leprosarium became relevant, since it went under the protection of Pope Innocent VI. Further records are in the late 14th century, with the involvement of the Magdalene complex in the events regarding the Western Schism. The architectural ensemble is composed by a barrel-vaulted room, the chapel, and two large vaulted rooms, the infirmary, previously used as a cistern for the rainwater collection. Actually only the wall-paintings, in bad conditions of conservation, testify the use as a sacred space of these rooms between 12th and 14th centuries. A careful survey of wall-paintings still visible in the chapel allowed to identify: on the northern wall a picture with Christ, or Virgin Mary, on the throne among male and female saints and an anonymous female donor, on the eastern wall a cycle of St Marina/Margaret of Antioch and a votive panel with three female saints. This is the most ancient wall-painted decoration preserved in a Medieval Leper hospital in Italy and Europe, dated to the last quarter of the 12th century. An accurate review of the paintings allowed us to examine in detail some unpublished elements that permitted us to redefine stylistic and iconographic aspects and, therefore, a chronological overview.