Introduction: Despite the evident recent advances in diagnosis and treatment of meningitis, the disease continue to be a leading cause of mortality and sequelae1. The overall mortality rates is about 6% to 12%3. The diagnosis and treatment depend on the clinical signs and CSF analysis. However, some biochemical markers have been studied previously with the aim of early diagnosis and management2. Aim of work: The aim of this study is to evaluate the levels of neuron specific enolase (NSE) and protein S100 в both in serum and CSF in cases with bacterial and non bacterial meningitis, as well as their relation to the outcome. Patients and Methods: The study included 48 patients (30 ♂ and 18 ♀) with acute meningitis admitted to the pediatric intensive care unit at Assiut children university hospital during the period from September 2008 to June 2009.The age ranged from 2 month – 6 years. The study also included 20 cases with matchable age and sex diagnosed as febrile convulsions were taken as controls. CSF examination (chemical analysis, CSF culture and Gram stain), blood culture, estimation of serum and CSF NSE and protein S100в were done to all cases and controls. Results: The levels of serum and CSF NSE were insignificantly different in cases with bacterial (41.3±9.1 ug/l and 21.5±8.1 ug/l respectively) than non bacterial meningitis (36.5±11.1 ug/l and 18.1 ±10.71 ug/l respectively) but significantly higher than controls (12.5±2.2 and 5.64±0.19). While the levels of protein S 100в in the serum and the CSF showed significantly higher levels in cases with bacterial (11.8±6.5 ug/l and 18.78±10.1 ug/l respectively) than non bacterial meningitis (4.5±3.4 ug/l and 10.3±3.4 respectively). The overall morbidity was 30.7% in bacterial versus 13.6 % in non bacterial meningitis. While mortality was 19.2 % in bacterial versus 9.1 % in non bacterial meningitis. In conclusion, CSF and serum NSE are reliable markers of brain damage in acute meningitis but cannot differentiate bacterial from nonbacterial meningitis. CSF and serum S 100в can be a helpful tool in differentiating bacterial from nonbacterial meningitis. CSF NSE may be used as a prognostic marker of outcome in bacterial meningitis. Their prognostic values need further studies following recovery