In this study, etiologic factors, morbidity and mortality ratio were evaluated retrospectively in a total of 244 central nervous system infection cases, between January 1998 and December 2004, in S.B. Ankara D›flkap› Teaching Hospital, Department of Infectious Diseases and Clinical Microbiology. Of 244 cases, 133 (54.5%) were bacterial, 81 (33.2%) were viral, 21 (8.6%) were tuberculous, 8 (3.3%) were Brucella meningitis and 1 (0.4%) was neurosyphilis. Cerebrospinal fluid cultures of 133 bacterial meningitis revealed Streptococcus pneumoniae in 16 (12%) cases, Neisseria meningitidis in 1 (0.8%) case, Acinetobacter spp. in 1 (0.8%) case, methicillin resistant Staphylococcus aureus in 2 (1.5%) cases, Pseudomonas aeruginosa in 2 (1.5%) cases, and Escherichia coli in 1 (0.8%) case. With regard to tuberculous meningitis cases, Mycobacterium tuberculosis was cultured in 2 (9.5%) cases. The highest morbidity ratio was in tuberculous meningitis cases followed by acute bacterial and viral meningitis cases. Of the 21 tuberculous meningitis cases, 7 (33.3%) cases had visual disability, 9 (42.9%) cases had confusion, 8 (38.1%) cases had focal neurological deficit, 10 (47.6%) cases had hydrocephalus. In the patients with bacterial meningitis 3 (2.3%) cases had hearing loss, 5 (3.8%) cases had visual disability, 7 (5.3%) cases had focal neurological deficit. Four of the patients with herpes encephalitis had behavioral disability. Sixteen (6.6%) bacterial meningitis, 8 (1.6%) tuberculous meningitis and 7 (2.9%) viral encephalitis were died. Case fatality rate was 11.1%