Borrelia burgdorferi infection, the tick-borne spirochetosis known as Lyme disease or Lyme borreliosis, involves the nervous system (neuroborreliosis) in 10% to 15% of patients. Common manifestations include lymphocytic meningitis, cranial neuritis, mononeuropathy multiplex, and painful radiculoneuritis. Rare patients develop inflammation in the brain or spinal cord. Regardless of the form of involvement, neuroborreliosis can be microbiologically cured in virtually all patients using standard 2- to 4-week antimicrobial regimens. Oral regimens appear to be as effective as parenteral ones in most instances. Although patients ill with Lyme disease may have concomitant cognitive or memory difficulty, these symptoms are not specific to neuroborreliosis and, when present in isolation, should not be viewed as suggestive of this diagnosis. When present as part of Lyme disease, they do not require additional or different treatment.