Analysis of the specific activity of cesium-137 in the fruiting bodies of representatives of the genus Leccinum collected during mass fruiting in the vicinity of the Seytesyavr Lake (Khibiny) showed that it does not exceed the permissible values. The data obtained can be used as reference data for comparison with the results of accumulation of cesium-137 by fruiting bodies of species of the genus Leccinum collected in other regions.