Between 01.01.2019 and 31.12.2021, 50 subjects with meningitis of different etiologies from the BacÄu County Emergency Hospital were analyzed. The study was conducted at the S.C. Medcenter S.R.L. Medical Analysis Laboratory, which serves the hospital. All 50 patients investigated in the 3 years of study were diagnosed with meningitis: viral (serous meningitis, acute serous meningitis, acute meningoencephalitis, acute viral meningitis), bacterial (meningococcal, pneumococcal, TB, staphylococcal, streptococcal and other bacteria). , fungal and an iatrogenic case. In bacterial meningitis cytology is characteristic, polymorphonuclear predominates (> 1000 elements / mmc). TB meningitis is characterized by the presence in the bacterioscopic examination of acid-alcohol-resistant bacilli (BAAR), which are highlighted on the Ziehl-Neelsen stained smear (it turns red on a blue background), and in cultures the presence of Mycobacterium tuberculosis. In viral forms, cytological examination shows the predominance of lymphocytes (500-1000 / mmc). The bacterial meningitis registered in the 3 years at the level of BacÄu county has as etiological agent: meningococcus 16%, Koch bacillus 8%, pneumococcus 8%, staphylococcus 6%, streptococcus 4%, E. coli 4%, H. influenzae 4%. At the level of BacÄu county, the viral forms had a share of 36% in the three years of study, but the bacterial meningitis, regardless of the etiological agent that produced them, were predominant (50%).