Lyme disease, caused by the Borrelia burgdorferi bacterium, is the most common vector-borne disease in the northern hemisphere. The clinical presentation varies with disease stage, and neurological manifestations (often referred to as Lyme neuroborreliosis) are reported in up to 12% of patients with Lyme disease. Most aspects of the epidemiology, clinical manifestation and treatment of Lyme neuroborreliosis are well known and accepted; only the management of so-called chronic Lyme disease is surrounded by considerable controversy. This term is used for disparate patient groups, including those who have untreated late-stage infection (for example, late neuroborreliosis), those with subjective symptoms that persist after treatment (termed 'post-treatment Lyme disease syndrome' [PTLDS]), and those with unexplained subjective complaints that may or may not be accompanied by positive test results for B. burgdorferi infection in serum (here called 'chronic Lyme disease'). The incidence of PTLDS is still a matter of debate, and its pathogenesis is unclear, but there is evidence that these patients do not have ongoing B. burgdorferi infection and, thus, do not benefit from additional antibiotic therapy. Chronic Lyme disease lacks an accepted clinical definition, and most patients who receive this diagnosis have other illnesses. Thus, a careful diagnostic work-up is needed to ensure proper treatment.