Antioxidant properties of mushroom extracts sequentially isolated by cyclohexane, dichloromethane, methanol, and water from Phaeolus schweinitzii, Inonotus hispidus, Tricholoma columbetta, Tricholoma caligatum, Xerocomus chrysenteron, Hydnellum ferrugineum, Agaricus bisporus and Pleurotus ostreatus were evaluated by DPPH, ABTS+ scavenging capacity, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and Folin–Ciocalteu total phenolic content (TPC) methods. The integrated values (‘antioxidant scores’) for evaluating antioxidant potential of extracts and dry mushroom substances are proposed. Antimicrobial activity was screened against Gram-positive (Bacillus cereus), Gram-negative (Pseudomonas aeruginosa) bacteria and fungi (Candida albicans) by agar diffusion method. The highest antioxidant capacity values (in μM TE/g extract dw) were found for methanol fractions of P. schweinitzii (9.62 ± 0.03 in DPPH; 109 ± 3 in FRAP; 164 ± 1 in ABTS+; 340 ± 3 in ORAC assays) and I. hispidus (9.5 ± 0.04 in DPPH; 54.27 ± 0.46 in ABTS+; 88.31 ± 1.96 in FRAP; 290 ± 1 in ORAC assays). Extracts of other species possessed considerably lower antioxidant activities. The extracts of I. hispidus were more effective against tested microbial species than other mushrooms. In conclusion, our results show that some wild mushrooms might be promising dietary sources of natural antioxidants and antimicrobial agents.