The goal of this study was the evaluation of antifungal, antioxidant and anticancer potentials of Pleurotus eryngii, P. ostreatus and P. pulmonarius mycelial extracts, and the influence of mycelium enrichment with selenium on these activities. Both Se-amended and non-amended extracts showed the same or similar minimal inhibitory concentration for 14 studied micromycetes, while a fungicidal effect was not noted, contrary to ketoconazole, which had inhibitory and fungicidal effects at very low concentrations. Se-non-amended extracts exhibited antioxidant activity, especially at higher concentrations. Selenium enrichment influenced activity, its effects decreasing in P. eryngii and P. pulmonarius, while in P. ostreatus no effect was noted. The DPPH? radical scavenging capacity of the extracts was in direct correlation with their phenol and flavonoid contents. Cytotoxic activity against both HeLa and LS174 cell lines was very low compared with cis-DDP. These features suggest that mycelium should be an object of intensive studies.