Application of PiCUS® Sonic Tomograph 3 in studies on the cultural heritage of the Lublin region – restoration of the Eastern Orthodox church of the Dormition of the Blessed Virgin Mary in Uhrusk. Uhrusk is a small town located in eastern Poland, in the Lublin region, along the border river, the Bug. The temple is situated on the outskirts of the village, on a low hill, where there was a castle founded by prince Daniel Halicki in the Middle Ages. The Orthodox church existed here before 1220, and for the fi rst decades of its functioning it had the status of a council. Today, the existing church building was erected in 1849 as a Greek Catholic temple founded by the owner of local estate, Laura Kirsztejnowa. In 1915, the church was abandoned when the Orthodox residents of Uhrusk became refugees. In the years 1920–1927, it was renovated, due to signifi cant losses suffered during the First World War and the Polish-Bolshevik war. The building was open again from 1920 to 1947, after which it was closed following the deportation of Orthodox Ukrainians as part of the “Wisła” Operation. At the end of the 1950s, the Orthodox church was restored for liturgical use as a branch of the parish in Włodawa. The style of the building is defi ned as classicist-Byzantine with neo-Romanesque and neo-Gothic elements. In 2017, on the initiative of the Dialog Foundation in Lublin, a general renovation of the temple building and its surroundings began. Studies conducted with the use of specialized diagnostic equipment in the form of a PiCUS® Sonic Tomograph 3 were important for the dendrological inventory. Within the boundaries of the property, 11 trees are growing, at different ages and in a healthy state. On the basis of the material collected, possible directions for the restoration of the Orthodox church’s surroundings were presented.