The results of our study of the hemoparasites of the lake frog inhabiting the North-Western Ciscaucasian reservoirs are presented. It was found that the parasites are represented by three species, namely: the sporozoa Hepatozoon magna and Dactylosoma ranarum, and Microfilaria. Differences in the erythrocyte morphology of the lake frog when infected by sporozoa were identified. Dactylosoma ranarum does not alter the size of the erythrocytes affected.