The updated checklist of Tuters Island (Leningrad Region, Russia) is presented. Of 331 species of recognized biota, 314 species of lichens, 16 lichenicolous fungi and one non-lichenized saprobic fungus are reported from Tuters Island. Of them, 202 species are new to the study area. Aspicilia epiglypta, Fuscidea praeruptorum, Micarea byssacea and Sarcogyne hypophaeoides are reported for the first time for Russia, Roselliniella stereocaulorum-for European Russia, Aspicilia polychroma, Carbonea vorticosa, Cercidospora stereocaulorum, Cladonia ciliata f. flavicans, C. rangiformis, Parmelia ernstiae, Plectocarpon cf. encausticum and Roselliniella cladoniae-for North-Western European Russia; Bachmanniomyces uncialicola, Bacidina sulphurella, Micarea botryoides, Miriquidica griseoatra and Stereocaulon nanodes are new to the Leningrad Region.