Lyme disease is a vector-borne infection primarily transmitted by Ixodes ticks and is caused by at least three different but closely related species of borrelia. Although it is the most common arthropod-borne disease in the U.S. and Europe, reports of the clinical cases have been relatively rare in Korea. The disease may affect different organs, such as nervous system, joints, heart or eyes, and the clinical pictures include meningitis, cranial neuritis, arthritis, temporary atrioventricular block, and conjunctivitis. The cutaneous manifestations are erythema(chronicum) migrans, borrelial lymphocytoma, and acrodermatitis chronica atrophicans. Early localized infection occurs a few weeks after a tick bite, and erythema migrans is a classic cutaneous manifestation at this stage of infection. Several weeks later, early disseminated infection occurs with bacterial dissemination. Multiple erythema migrans-like skin lesions, neuroborreliosis, arthritis, and carditis can develop. Without treatment, the disease can progress to late or chronic infection, and then acrodermatitis chronica atrophicans may develop in addition to the systemic manifestations. The disease can be diagnosed with serologic tests such as indirect immunofluorescence test or ELISA. The recommended treatment is oral doxycycline or amoxicillin, and the treatment period is variable depending on the organ involved and the duration of the disease. A vaccine for the Lyme disease is approved for adults and commercially available in the Unites States. However, protection from tick bites by the use of protective clothing in risk areas and body inspection and removal of any attached ticks as soon as possible are the most important prophylactic methods. Chemoprophylaxis after a tick bite is also available.