Borrelial infection may manifest with a wide range of clinical signs, and in many cases, microbiological findings are essential for a proper diagnosis. This study included 48 patients with a working clinical diagnosis of Lyme neuroborreliosis, 45 patients with a working clinical diagnosis of suspected Lyme neuroborreliosis, and a control group comprising 42 patients with tick-borne encephalitis and 21 neurosurgical patients. The aim of the study was to analyze and compare findings of two PCR methods and Borrelia burgdorferi sensu lato culture results by examination of prospectively collected cerebrospinal fluid (CSF) and blood specimens from patients with clinical features of Lyme neuroborreliosis. Borrelial DNA was detected with at least one of the PCR approaches in 16/135 (11.9%) blood samples and 24/156 (15.4%) CSF samples. Using MseI restriction of PCR products of the amplified rrf-rrl region, we identified the majority of strains as Borrelia afzelii. Borreliae were isolated from 1/135 (0.7%) blood samples and from 5/156 (3.2%) CSF specimens. Using MluI restriction for characterization of isolated strains, Borrelia garinii was identified in all CSF isolates. Our study revealed that different approaches for direct demonstration of borrelial infection give distinct results, that there is an urgent need for standardization of the methods for direct detection of borrelial infection, and that the design of studies evaluating the validation of such methods should include appropriate control group(s) to enable assessment of both sensitivity and specificity.