Lyme disease affects the nervous system in about 10% to 15% of infected individuals, most commonly causing lymphocytic meningitis. Cranial neuropathies, particularly facial nerve palsy, also occur frequently. Figuring prominently in the European literature, but less emphasized in the United States, is painful radiculitis, radicular pain involving a limb or trunk dermatome. Treatment of neuroborreliosis is usually straightforward; oral antibiotics may suffice in many patients. In severe cases, 2 to 4 weeks of parenteral therapy is necessary. All available evidence indicates that treatment of more than 4 weeks' duration carries substantial risk but minimal if any additional benefit.