The state of conservation of some tombs in the Jewish Cemetery of Algarrobos in Colonia Mauricio, Buenos Aires, Argentina was evaluated. A lot of material was found, but only two tomb-markers were done on wood. They were in a state of serious deterioration, so these were defined as an object of study. The tomb-markers, which had been established by the Jewish immigrants from Russia at the end 19th century, were made of South American tree known as Aspidosperma Quebracho Blanco and suffered both biological (from fungal decay and insect attack) and mechanical deterioration (cracks and fissures due to weathering, and discoloration due to ultraviolet radiation). Thus, the aim of this paper was the conservation of one of the two remaining wooden tomb-markers found, using impregnant based on non-toxic siloxanes employing sol-gel technology in order to increase the readability of epitaphs and reliefs found at the tomb-marker. The treatment with this modern technology resulted in the excellent performance of wooden tomb-maker conservation. The structural consolidation and cracks sealing were achieved. It avoided the detachment of material and the appearance of natural veins; furthermore, it improved the reading of the epitaphs and reliefs.