An account is given of a first exploratory study on the prevalence or antibodies against Borrelia burgdorferi among Dutch forestry workers and on the association of seropositivity with signs and symptoms suggestive of Lyme disease and with medical and occupational history. Of the 127 participants 25 (20%) had serological evidence of past or present infection. Most infections were asymptomatic. Furthermore, methodological considerations are given for a possible follow-up study, with regard to prevalence, incidence, natural history, serological testing and preventive measures.