The analysis of the occurrence of aphyllophoroid fungi on islands of the Kiy Archipelago (Onezhskiy District, Arkhangelsk Region) is carried out for the first time. In total, 150 species of aphyllophoroid fungi were revealed. Among them, 10 species (Amylocorticium suaveolens, Athelia phialophora, Atheloderma orientale, Dichomitus campestris, Odonticium septocystidia, Oxyporus millavensis, Postia floriformis, P. perdelicata, Scytinostroma parvisporum, Xylodon detriticus) are indicated for the Arkhangelsk Region for the first time. A majority of the species revealed are saprotrophs on dead wood. The highest number of species (65) was recorded from Pinus sylvestris - the main stand-former in the archipelago. In local areas of floodplain ecotopes 36 alder-associated and 32 willow-associated species were recorded. Because of heavy human pressure on the archipelago's ecosystems, only 7 ground-dwelling aphyllophoroid species were revealed (Coltricia perennis, Hydnellum aurantiacum, H. ferrugineum, H. suaveolens, Phellodon tomentosus, Sarcodon imbricatus, Thelephora terrestris). Botryohypochnus isabellinus was found on fruit bodies of basidiomycetes, and Typhula setipes was spotted on fallen alder leaves. 18 species are considered as indicators of biologically valuable forests, 7 species are included in regional Red Data Books.