The article represents the results of the complex petroarcheological study focused on the building material with respect to the restoration of the old fortified monastery Bzovík (Central Slovakia). The aim of the study was to determine the original building material and to suggest the best solutions of the building recovery. The petroarcheological study enabled to describe the present state of the used rocks, their resistance and several types of mortars. The aim of the study was determining the material of building We found that the majority of the building stones are from the Neogene volcanics of the Štiavnica stratovolcano. Mainly effusive and extrusive activity of andesite volcanism. Distinguish the original and more new additional building elements, suggest suitable procedures and materials with respect to the sanitation of the building complex.