Serum samples from 921 apparently healthy individuals living in different prefectures of Northern Greece were investigated for the presence of antibodies against tick-borne encephalitis (TBE) virus. In addition, serum and cerebrospinal fluid samples of 302 patients with central nervous system (CNS) infection were tested for the presence of specific IgG and IgM antibodies and TBE virus RNA. Two percent of the general population was found to have antibodies to the virus, with no significant differences among the age groups. Most of the seropositive individuals were male farmers, while seroprevalence varied among different prefectures (0%-5.8%). TBE was not confirmed by laboratory findings in any of the patients with CNS infection. Results of this study revealed that a flavivirus of the TBE serocomplex is circulating in Greece, yet is not a major public health problem.