Lyme disease is a tick-borne disease, and recognized as a complex, multisystem disorder. An outbreak [correction of outback] of Lyme disease was first described in the United States in the 1970s. The presence of Borrelia burgdorferi, its causative agent, in the skin results in the development of characteristic expanding red skin lesions, erythema migrans (EM). EM may be associated with cardiac abnormalities, meningitis, and cranial peripheral neuropathies. Arthritis, neurologic and skin manifestations may persist for several years and become chronic in a small percentage of patients. Studies on the classification of B. burgdorferi resulted in the identification of three closely related genospecies, and different clinical manifestation of Lyme disease have been correlated with the infecting genospecies. The diagnosis of Lyme disease should be based primarily on the clinical presentation, epidemiological information and serological tests. Antimicrobials are effective in the treatment of Lyme disease in most patients. Lyme disease is a zoonosis and endemic in areas where suitable mammalian reservoirs for B. burgdorferi and appropriate hosts for the tick vector are present. According to changes in the natural environment, the distribution of infected ticks and reservoirs is anticipated to expand.