In the Yaroslavl region (Central Federal District of Russia), endemic of tick-borne encephalitis (TBE), the features of epidemiology of this infection were studied during 1992-2012. Cyclical fluctuations in the incidence of TBE, the lack of the trend to decrease of the incidence were observed, the average annual incidence was 1,6 ± 0,32 per 100 thousand ofpopulation. The prevalence offebrile forms of disease was 62,2%, meningeal forms - 16,3%, the total percentage offocal forms was 13,9%. Manifestations of evolution of TBE were: the increase of the epidemiological significance of anthropogenically transformed natural foci, anthropurgical foci of TBE, until 81% of TBE cases were unvaccinated citizens, the high lethality of 4% and the high frequency of cases of alimentary infection of TBE of 7,8% with lethality of 10,8%. The aethiological agent of 10 lethal cases was Siberian subtype of TBE virus.