Plant-microbial interactive relations with respect to determine mycoflora of the Sorbus domestica L. - fruits, crust, leaves and pollen were studied in 2 Slovak regions. On the fruit samples the genera Alternaria, Botrytis, Cladosporium, Mucor and Penicillium occurred, on the leaves the genera Alternaria, Cladosporium and Penicillium prevailed and on crust the genera Alternaria, Cladosporium, Penicillium and Trichoderma appeared to be dominant, respectively. Isolates from the Sorbus domestica L. fruits were present by 11 genera and 13 species of microscopic fungi and isolates from pollen such as Alternaria, Botrytis, Cladosporium, Penicillium, Mycelia, Mucor and Trichoderma appeared to be the most frequently occurring genera. On the basis of further taxonomic determination, from the genera Aspergillus were isolated and identified representatives of species A. clavatus, A. fumigatus, A. niger, A. ochraceus, A. terreus. It is necessary to point out that the isolated genera Aspergillus and Penicillium are considered as the most important producers of mycotoxins.