Conservation intervention of the mural paintings with calciun hydroxide nanoparticles. It was the first intervention in Lombardy in which have been applied, for the consolidation of the painted surfaces, the nanophases of calcium hydroxide. The results of this work contributed to the improvement of the application techniques and have been presented during the meeting organised by FAST (Federation of the Scientific and Technical Associations) and subsequently to the first Argentine Archaeometry congress at the Universidad Nacional de Rosario.