Twenty two species of Culicidae (47% of Polish fauna) were recorded in the vicinity of Wyskok in Polish Masurian Lakelands. Eight species of mosquitoes were recorded for the first time in the Masuria. Another 8 species are rarely recorded in Poland. Females of Coquillettidia richiardii (FICALBI), Aedes cinereus MEIGEN and Ochlerotatus cantans (MEIGEN) were the most aggressive in relation to a man.