The analyses reported in the present paper aimed at determining the species composition and spore concentrations of airborne fungi in bear dens. Aeromycological analyses inside the dens were performed with the impact method using an Air Ideal 3P apparatus. Five bear dens were included in the survey – all located within Tatra National Park in southern Poland. Four dens had been used by females with one young or by solitary individuals, and another one had not been used for several years. The aeromycological analysis of the dens revealed the incidence of 13 species of fungi. Inside the dens in which the females with young had hibernated, the majority of spores represented the genus Penicillium. In the remaining dens the highest concentrations of spores were produced by the species P. glaucoalbidum. Furthermore, the airborne spores of Aspergillus niger, Botrytis cinerea, and Trichoderma spp. were found in the dens surveyed. In the dens used by females with young, the concentrations of CFU/m³ were lower, but the number of species of fungi was higher compared to the ones in which no young individuals hibernated. In the latter dens the values of CFU/m³ reached levels potentially dangerous to human health.