There have been a few severe cases of tick-borne encephalitis in Liechtenstein during the last 20 years. To form a better idea of the risk of infection and the potential benefit of vaccination, a total of 311 sera from different cohorts were investigated for antibodies to tick-borne encephalitis. The mean seroprevalence found was 3.6% and was not higher even in persons who were active in professional forestry. The antibodies measured derived in all groups mainly from previous vaccination and in only 2 cases (0.6%) from natural infection. It is concluded that the risk of TbE infection in Liechtenstein is very low. Therefore, a reduction in cases would probably be achieved only by mass vaccination.