We included in our study 18 patients hospitalized because of tick borne encephalitis (tbc) at the Departament of Infectious Diseases and Neuroinfections of Medical University of Bialystok. In this group, concentration of vitamins A, E and C in serum and cerebrospinal fluid (CSF) was measured before and after treatment. The control group consisted of 11 patients with no inflammatory changes in CSF were observed. We did not observe significant differences in concentration of vitamins in serum and CSF before and after treatment comparing to controls. However, we showed significant increase in concentration of vitamin E before and after treatment in both serum and CSF in patients with tbc in comparison with control group.