Records of patients aged 0 to 15 years, hospitalised between 1993 and 1998 at the intensive care unit (ICU) of the Department of Infectious Diseases, Ljubljana, Slovenia, suffering from a severe attack of tick-borne encephalitis (TBE), were reviewed. Of 133 children hospitalised due to TBE virus infection during the observation period, 7 (5.2%) were treated in the ICU. All patients were male, aged 6 to 14 (mean, 11.1) years. In six cases, focal encephalitis was diagnosed, and in one case it was suspected. All patients survived. After a mean follow-up period of 7.9 (range, 1.5 to 17) months, one patient was found to have severe neurologic sequelae and two patients had moderate sequelae. In conclusion, the results of our retrospective study of severe forms of TBE in children demonstrate that this disease can run a severe course and may lead to permanent sequelae, most often in boys of school-going age who present with focal encephalitis. Therefore, immunisation of school children against TBE in endemic areas is strongly recommended.