Clinical and serological examinations were carried out in 60 patients with Lyme disease. The diagnosis was established on the basis of the disease marker--tick-borne migrating erythema and serological data obtained with the use of indirect immunofluorescence and Western blot. The spectrum of clinical manifestations and the rate of different clinical syndromes are described and compared with the data by this country and foreign authors. It is shown that Borrelia infection is capable of imitating rheumatic diseases.