The revealed lichen diversity of the proposed protected area Motornoe-Zaostrovje counts 452 species, including 400 lichens, 34 lichenicolous fungi, four facultatively lichenicolous fungi, and 14 non-lichenized saprobic fungi. Micarea synotheoides and Tremella hypocenomycis are new to Russia; Rhizocarpon sublavatum is new to European Russia; Absconditella celata, Biatora albidula, Cyphobasidium hypogymniicola, Karschia talcophila, Micarea melanobola, Pyrenula laevigata, Sclerococcum microsporum, Sphinctrina anglica, and Trapeliopsis glaucolepidea are new to North-Western European Russia; Arthrorhaphis alpina, Lecaimmeria cupreoatra, Micarea nowakii, Protothelenella petri, Pycnora xanthococca, and Sagedia simoënsis are new to the Leningrad Region. Of particular interest are lichens of old-growth spruce forest in the Rytovka stream valley in its middle course. The lichen biota of Motornoe-Zaostrovje is one of the richest lichen biotas known in the Leningrad Region. It comprises 32 red-listed species, 20 habitat specialists (i. e., species restricted to biologically valuable forests) and 24 indicator species, and deserves protection on the regional level. Key words: Micarea synotheoides, Tremella hypocenomycis, protected areas, Isthmus karelicus.