The diploma thesis is focused on the evaluation of differences in species richness and composition of molluscan communities, depending on the overstorey tree species composition and the age of the forest stands. The Poľana Mts. was chosen as the area of interest. The diploma thesis follows the research of the bachelor thesis (ĽALÍKOVÁ 2016), where the snail communities of secondary managed forests and primeval forests of the Zadná Poľana reserve were evaluated on 24 localities. A total of 45 localities were selected for the research of the diploma thesis, with 30 of them situated in secondary managed stands (15 beech and 15 spruce) and 15 in the Zadná Poľana National Nature Reserve. In managed spruce and beech stands, plots were selected based on three age classes (25-45, 60-70, >100 years). Malacological research was carried out between June and October 2017, with 12-liter material being collected from each plot. In the Poľana Protected Landscape Area, 3661 species belonging to 62 species of molluscs were recorded in 45 localities. The mesophilic species Punctum pygmaeum was the only one found in all the plots surveyed. The highest number of species (57) and individuals (1515) were recorded in the Zadná Poľana reserve. Within the secondary stands, the highest mean number of species and individuals were found in the 25-45-year-old stands, while the lowest mean number of species and individuals were recorded in the old (>100 years) stands. The GLM-based analysis showed that the managed stands were significantly different by the number of molluscan species depending on their age (χ = 11.57; p = 0.003). Similarly, the influence of the dominant overstorey tree species was also statistically significant (χ = 4.04; p = 0.045), meaning that the stands differed in the number of species depending on whether they were beech or spruce ones. Based on the results of perMANOVA, the malococoenoses significantly differed in terms of their species composition among three stand age classes (pseudo-F = 3.59, p < 0.001). Statistically significant effect of overstorey tree species on molluscan community structure (perMANOVA, pseudo-F = 4.12, p < 0.001) was also proved. Other factors influencing the molluscan species richness and composition of the communities were, in particular, the amount of dead wood and the presence of valuable broadleaves (sycamore maple, common ash).