Acute viral infections of the central nervous system (CNS) are among the most serious medical problems due to difficult diagnosis and time-sensitive treatment. The aim of this prospective study is to summarize the major clinical and laboratory manifestations of viral neuroinfections (NIs) in hospitalized patients in Specialised Hospital for Active Treatment of Infectious and Parasitic Diseases (SHATIPD) “Prof. Iv. Kirov” in Sofia, during the period 2011-2022. The analysis includes 88 patients with viral meningitis etiologically verified via cerebro-spinal fluid (CSF) analysis by multiplex Polymerase-Chain Reaction (PCR) often combined with Flu A/B antigen tests. The results show that 82 (93.1%) of the patients exhibited pronounced initial toxico-infectious syndrome, accompanied by symptoms of nuchal rigidity – 68 patients (77.2%), Kernighan’s sign – 62 patients (70.4%), and changes in tendon reflexes – 55 patients (62.5%). The mental status according to the Glasgow coma scale showed a low level of consciousness during the severe disease. A total of 43 (48.8%) patients were etiologically diagnosed; in the remaining 44 (50.0%) no infectious viral/ bacterial agent was identified. The causative viruses found were as follows: enteroviruses – in 13 patients (30.2%), Varicella Zoster Virus (VZV) – in 11 patients (25.5%), and influenza viruses – in 10 patients (23.2%). Cases with meningoencephalitis caused by influenza viruses were documented with the most severe course, followed by those caused by the Herpesviridae family. The data presented here cover roughly a 10-year observation period with the most commonly encountered causative agent for NIs being enteroviruses which corresponds with findings published by other authors. The combination of acute onset fever with nuchal rigidity, Kernighan’s sign in addition to upper Brudzinski and low consciousness, are an important early indicator for NIs requiring a diagnostic lumbar puncture. Despite the enormous strides to earlier diagnosis of NIs, additional effort is still necessary to shorten this time and to improve the prognosis with the appropriate treatment.