The interest in studying the fauna of horseflies in the Tyumen region is based on a pronounced zonal distribution covering almost all areas (except the steppe) of Russia, and geography: to the east of the Ural Mountains separating two continents, and is associated with intensive development of this territory having the richest deposits of oil and gas. This article systematizes and summarizes the available literature data and materials of own researches. Intensive study of the species composition of horseflies of the Tyumen region was carried out in the period from the 60s to the 80s of the last century. Currently, it is a topic of interest of just some individual researchers. Data are available on the ecological-faunal survey of horseflies (Diptera, Tabanidae) of the middle taiga of Western Siberia (Dukhin, 2009), on the fauna of Tobolsk and Tobolsk District (Maslovskaya, 2016), Kurgan Region (Agapitova & Balakhonova, 2011). The faunal list of horseflies of the Tyumen region includes 42 species and one subspecies of six genera, including Chrysops-6, Tabanus-6, Atylotus 4, Hybomitra -20 species and one subspecies, Heptatoma-1 and Yaematopota-5 species. Dominant and subdominant, causing the most inconvenience to the animals on pastures, within one season are 6-7 species, which together account for more than 90% of the attacking horseflies, and according to long-term data, their number reaches 13-14. Horseflies are distributed unevenly on the territory of the region, due to natural and climatic factors. Horseflies can not be found in the typical tundra. Moving to the south of the region, the number of their species increases from 6 in the area of shrub tundra to 35 in the south of the forest area. The fauna is growing both due to the appearance of species characteristic for the given area and due to their penetration from neighboring zones and subzones. Of the 43 species and subspecies of horseflies, 24 are potential vectors of agents of various human and animal diseases. On pastures, where there is the highest concentration of parasitizing horseflies, their vector role becomes especially dangerous if there are sick animals in the herd.