Zoogeographic analysis of cestodes in fishes from lakes of Karelia was carried out. It is demonstrated that cestodes in fishes living in Karelia belong to 5 faunal complexes and 1 (brackish-water) group. The core of the cestode fauna in fishes of Karelia is constituted by 2 faunal complexes – arctic and boreal-flatland ones. The species diversity of cestodes decreases from south to north, with a redistribution of the proportions of faunal complexes. Northern Karelia and Kola Peninsula are similar in the species composition of cestodes, whereas southern Karelia shows great similarity to waterbodies of the Baltic watershed. The natural boundary between them is the Baltic-White Sea drainage divide, which is the northern limit of the distribution ranges of 9 cestode species: parasites of sticklebacks Diphyllobothrium vogeli, Schistocephalus solidus, Proteocephalus ambiguus, as well as cestodes specific to eel Bothriocephalus claviceps and Proteocephalus macrocephalus, sculpin Bothriocephalus scorpii, smelt P. tetrastomus, cat-fish Silurotaenia siluri, loaches P. sagittus. The northern distribution limit for two cestode species – a parasite of cyprinids Caryophyllaeus laticeps and of grayling P. thymalli, is northern Karelia. High similarity was detected between cestode faunas of the Baltic and the Arctic oceanic provinces.