Forestry workers in Saitama Prefecture are in high occupational risk to Lyme borreliosis transmitted by ticks. We surveyed the incidence of tick bites and the prevalence of antibodies against Borrelia burgdorferi in 80 forestry workers. ELISA with the antigen from B. burgdorferi sensu stricto B31 as well as Borrelia garinii HP3 and Borrelia japonica HO14 isolated in Japan was used for the detection of antibodies. Antibody-positive cases against B31, HP3 and HO14 was 3.8, 23.8 and 13.8%, respectively. Antibody-positive cases by ELISA were subjected to Western blotting with the antigens from three borrelias. Finally, 20.0% of the workers were antibody-positive by specific antibodies, anti-OspA antibody. The correlation between ELISA and Western blotting was better when HP3 was used as an antigen. One out of 30 normal control individuals was positive in ELISA with HP3 antigen, but negative in Western blotting. Thirty percent of the workers had a history of tick bites, and these cases had no characteristic symptoms of Lyme borreliosis. However, the rate of tick bites in antibody-positive cases was significantly higher than that in antibody-negative cases. These results suggested that the forestry workers in Saitama are very likely to be infected with Lyme borreliosis transmitted by ticks.