In 1992/93 6202 ticks (Ixodes ricinus) were tested in Mecklenburg-Vorpommern for Borrelia burgdorferi via dark-field microscopy. The prevalence of infected ticks was 7.8%. The sera of 1182 forest workers in Mecklenburg-Vorpommern were tested for antibodies against Borrelia burgdorferi. In 31.4% antibodies to B. burgdorferi were found in the sera of forest workers.