Borrelia burgdorferi is the causative bacterial agent of Lyme borreliosis, a tick-transmitted infectious disease. The Dutch Institute for Health Care Improvement (CBO) has now issued a guideline on 'Lyme borreliosis'. Lyme borreliosis is classified as 'early', 'early disseminated', 'late' or as 'post-infectious complaints and symptoms'. Erythema migrans is the most common manifestation of early Lyme borreliosis. Frequent neurological manifestations of 'early disseminated Lyme borreliosis' include meningoradiculitis, meningitis and peripheral facial palsy, but Lyme carditis and arthritis also occur. Late Lyme borreliosis is characterised by skin abnormalities (acrodermatitis chronica atrophicans), chronic neuroborreliosis or chronic arthritis. Confirmation serology with respect to Borrelia is the most commonly used laboratory technique, but in early Lyme borreliosis the immune response may be absent. In addition, the mere presence of antibodies in the serum is no proof of an active infection with Borrelia and serology may yield false-positive reactions. Doxycycline and ceftriaxone are the most commonly used antibiotics in the various stages of Lyme borreliosis. Lyme borreliosis may be prevented by avoiding high-risk areas, keeping the skin covered as much as possible, and inspection of the skin after possible exposure to remove ticks within 24 hours. Laboratory tests after a tick bite are not recommended, nor is prophylactic treatment with antibiotics.