Eight new species of fungi (Acanthobasidium norvegicum, Amylocorticium laceratum, Hyphoderma transiens, Odonticium septocystidiatum, Phlebia cretacea, Ph. subulata, Steccherinum albidum, and Tubulicrinis calothrix) were identified for Poland after a study of collections from large forests situated in the northeast part of the country. Leptosporomyces fuscostratus was confirmed for Polish mycobiota. Main diagnostic features, natural range, substratum preferences, and taxonomic position of these species are discussed. Color images of basidiomata for 9 species, line drawings of microscopic structures for 6 species, and scanning electron microscopy images of important microstructures for 4 species are provided.