Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymp-tomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are com-mon to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl ad-mitted to São Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admis-sion and discontinued after negative laboratory results were obtained. Nine days after symp-toms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations, and emphasizes that its possible involve-ment might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.