The most common cause of Lyme neuroborreliosis in Europe is Borrelia garinii, followed by Borrelia afzelii. However, no series describing patients with culture-confirmed cases of Lyme neuroborreliosis have been published, and no comparison of findings for patients with B. garinii and B. afzelii isolated from cerebrospinal fluid (CSF) has been reported.All adult patients identified at a single medical center during a 10-year period who had borreliae isolated from CSF and typed as B. garinii or B. afzelii (using large DNA fragment patterns obtained with the MluI restriction endonuclease and separated with pulsed-field gel electrophoresis) were included.A comparison of 23 patients who had B. garinii isolated from CSF with 10 patients who had B. afzelii isolated from CSF revealed that a reliable clinical diagnosis of Lyme neuroborreliosis (before obtaining a CSF culture and intrathecal borrelial antibody production result) was established more frequently in the B. garinii group than in the B. afzelii group (19 of 23 patients vs. 1 of 10 patients). Patients in the B. garinii group reported radicular pains and expressed meningeal signs more often, but reported dizziness less often (occurrences of several other symptoms and/or signs were comparable). Lymphocytic pleocytosis, as well as several other CSF abnormalities, were frequent among patients with B. garinii isolated from CSF but were rare among patients in the B. afzelii group.Patients with B. garinii isolated from their CSF have a distinct clinical presentation, compared with patients with B. afzelii. B. garinii causes what, in Europe, is appreciated as typical early Lyme neuroborreliosis (Bannwarth syndrome), whereas the clinical features associated with B. afzelii are much less specific and more difficult to diagnose.