Tick-borne encephalitis (TBE) is caused by tick-borne encephalitis virus (TBEV), a virus species of the genus Flavivirus within the Flaviviridae family. In Western Europe, TBEV is transmitted primarily by the Ixodes ricinus (I. ricinus) tick. During the last 30 years, there has been a continued increase in human cases of TBE in Europe. A total number of 102 cases in Slovakia was reported in 2012 (1.89/100,000), with two local outbreaks after the ingestion of raw milk and dairy products. Active vaccination is the most effective method of preventing TBE. According to the available data in Slovakia from 2012, 8,491 children under 15 years of age were vaccinated that year, which, when compared to 2009 with approximately 17,000 vaccinated children, represents a decrease of more than 50%. The data on vaccination of adults are not available, but the estimated vaccination coverage in Slovakia is around 1% (1.3/100,000). The education of the population is also an important precautionary measure in the prevention of tick-borne illnesses.