The paper discusses epidemiological and clinical data as well as therapeutic and diagnostic methods with regard to Lyme disease. Main manifestations of early (erythema migrans, borrelial lymphoma, Lyme carditis, neuroborreliosis and Lyme arthritis) and late (neuroborreliosis, Lyme arthritis, acrodermatitis chronica atrophicans) Lyme borreliosis are described and their treatment is discussed. The most useful antibiotics are doxycycline and ceftriaxone. It was noted that in most cases of Lyme disease the prognosis is good, and antibiotic treatment is very effective regardless of the stage of infection. Detection of specific anti-Borrelia burgdorferi antibodies in a patient with a history of a tick bite and clinical symptoms suggesting Lyme disease is necessary for diagnosis. The results of serological tests must be interpreted carefully and always in connection with the clinical picture. A seropositivity without clinical symptoms of the disease does not necessarily prove an active infection. Antibody serum titres should not be used to assess therapeutic efficacy or be regarded as an indication for a re-treatment. Current recommendations stress that detection of chemokine CXCL13, searching for B. burgdorferi antigens in the cerebrospinal fluid and urine, searching for B. Burgdorferi spheroplasts or L-forms as well as CD57+/CD3 subpopulation assessment as well as lymphocyte transformation test have no confirmed diagnostic significance in Lyme disease diagnostics.