The purpose of the researchis establishing the composition, infection rates, species and group ratio of ectoparasites of the East European vole on the northern border of the range in Western Siberia (Middle Ob Region).Materials and methods.In 2015–2018, in order to capture the provider of ectoparasites, the East European vole, we used methods of trap lines, trap trenches, and fence-traps; we recorded 173 animals from which we collected 881 specimens of gamasid mites, ixodic ticks, lice and fleas. To assess the quantitative indicators of ectoparasites, the indices generally accepted in parasitology were used.Results and discussion.In 2014, it was established for the first time that there is a sibling species of the common vole, the East European vole in the Middle Ob Region (middle taiga of the forest zone of Western Siberia). In the city of Surgut and its neighborhood, this animal is confined to the most transformed biotopes. The ectoparasite complex of the East European vole includes 26 species of parasitic arthropods. By the number of species (13) and individuals, gamasid mites predominate, and the proportion of ixodic ticks, lice and fleas put together is almost 3 times lower. In a climate of the Middle Ob Region, the list of ectoparasites will no doubt grow as the range of habitats expands and the contacts of the East European vole with other small mammals increase, and its role in maintaining pathogen circulation of natural focal infectious diseases will increase.