Objective. To evaluate the efficacy of different methods of antivirus therapy of tick-borne encephalitis (TBE) in children in the acute period and during chronic infections. Material and methods. During 1 year, 130 children, aged 7—17 years, with TBEV received therapy in the acute period (an average in 3.5±1.3 days) in groups 1 (n=84) and 2 (n=20), and in the chronic infection in groups 3 (n=15) and 4 (n=11). Ribavirin orally, recombinant interferon-α2 (IFN-α2) i/m or in suppositories and anaferon orally were prescribed to children of groups 1 and 3. Children of groups 2 and 4 received tick-borne immunoglobulin (IgG)i/m and ribonuclease i/m. At admission, all patients received infusions of cytoflavin in the drip at the rate of 0.6 ml/kg per day. Etiological diagnosis included ELISA (IgM, G, viral antigen), and virus RNA by PCR in the blood and CSF. MRI of the brain and cervical spinal cord using standard programs was performed. All studies were performed prior to and in the course of treatment. Results and conclusion. In patients of group 1, the period of increase in symptoms was reduced by ~ 4 days, and the duration of impairment of consciousness and pleocytosis in CSF ~ by 5 days, which was accompanied by a faster clearance of the virus in CSF, compared with group 2. In group 1, recovery without neurological deficit was observed in 83.3% (n=70), all patients had no progression of infection. In group 2, 30% of children (n=6) acquired TBEV chronic infection, and in 55% (n=11) there was a neurological deficit without progression. In patients of group 3 with chronic TBEV, the improvement was observed in 86.7% of cases, and complete regression of symptoms occurred in 1 patient, and replication of the virus was arrested in all of them. In group 4, symptoms increased in 72.7%, while virus replication was preserved and atrophic changes in the CNS increased on MRI. Antiviral therapy (ribavirin, IFN-α2 and release of active antibodies to gamma interferon -anaferon children) has the highest efficacy when prescribed for the first 5 days, while IgG and ribonuclease have insufficient efficacy in TBEV.