The Restoration of the Church of St. Mary Major in Spello involved the following areas: the stone ciborium, the wall face and plastered surfaces, the stucco and wooden elements, and finally the wall paintings. Limited to this last area, the intervention was localized in the degraded areas; in this case, the possible fall of portions of plaster, in addition to causing a very serious damage to the integrity of the pictorial cycle of Pinturicchio, represented a danger to the frequenters of the Chapel. The work was preceded by an inspection of the entire surface performed with a lifting platform and scaffolding. The check was performed by tapping the plaster surface to ascertain the presence of any detachments. Plaster areas with defects in adhesion to the substrate were mapped, and restoration work was performed on the graphed areas. Fixing was done by injection of CTS’s PLM hydraulic mortars and grouting with Lafarge marble-lime powder mortar.