Original material on the louse flies parasitizing birds in the Republic of Karelia was summarized. Based on published data and own collections we compiled the list of louseflies, comprising 8 species: Ornithophila metallica, Ornithomya avicularia. O. chloropus, O. fringillina, Crataerina (Stenepteryx) hirundinis, C. obtusipennis, Icosta ardae and I. minor. For four species, Ornithomya avicularia, O. chloropus, O. fringillina, and Crataerina hirundinis, breeding inside the region has been proved. The possibility that another four species, Ornithophila metallica, Crataerina obtusipennis, Icosta ardae, and I. minor, are brought in by migratory birds is considered.