The use of microscopy, infection of golden hamsters and the polymerase chain reaction made it possible to find out that about 30% of common red-backed voles (Clethrionomys glareolus), inhabiting the taiga forests of the southern part of the Western Urals (the Chusovskoi district of the Perm region), were infected with Babesia microti and simultaneously (a third of them) with Ehrlichia (Cytoecetes) phagocytophila, the causative agent of granulocytic ehrlichiosis. The sequencing of 18S rDNA of strain "Mys", isolated in Russia, revealed its identity to American B. microti strain GI, pathogenic for humans. The main vector supporting the circulation of B. microti in the natural foci in the region where these investigations were conducted was, seemingly, the tick Ixodes trianguliceps, Thus, for the first time the data proving the presence of reservoir hosts infected with B. microti and granulocytic E. phagocytophila, pathogenic for humans, in Russia were presented.