The chapel of the Madonna del Rosario is located to the left of the main altar and was affected by notable landslides and alterations mainly caused by infiltrations of rainwater from the covers and to a lesser extent by rising damp. The causes of the infiltrations appear to have been eliminated but the alterations caused by them remained, mainly due to the abundant migration of soluble salts into the surface that has put in serious danger the sealing of the decorative apparatus present; therefore, the primary treatment was aimed at the removal of salt efflorescences and subsequent consolidation of the surfaces. Only after restoring the cohesion of the plaster-layer system were the reintegration operations performed at the level of the gaps and the aesthetic restoration of the decorated surfaces.