This study documents 36 new lichen species for Kunashir Island, thereby bringing the total number of known lichens and lichenicolous fungi on the island to 430. The species Agonimia pacifica and Parmelia marmorophylla are reported for Russia for the first time. Cliostomum leprosum, Pseudosagedia borreri, Thelocarpon superellum, and Trapelia corticola are new to the Russian Far East. Julella sericea, Micarea botryoides, and Muellerella lichenicola are new to the Sakhalin Region. Six species are reported for the Kuril Islands for the first time. For each species, the nearest known locality is provided. For rare lichens, differences from closely related species are discussed. As a result of the revision, Agonimia tristicula and Micarea xanthonica were redefined and excluded from the Sakhalin Region checklist. Keywords: Agonimia pacifica, Asia, distribution, new records, Parmelia marmorophylla, rare species, Russian Far East.