Bacterial meningitis is an important disease world wide and if remains undiagnosed and not treated in time is associated with irreversible and serious complications and a high morbidity and mortality. This retrospective study was conducted on 90 patients who met the criteria of acute bacterial meningitis and who were admitted at the pediatric Medical center and lmam khomeini Hospitals between 1999-2000 . According to this survey, the important factors affecting the prognosis at discharge included age less than 12 weeks, no response to antibiotics 72 years after initiation of treatment, altered consciousness at the time of admission, focal NEUROLOGICAL symptoms and a change in antibiotic regimen. No correlation was found between prognosis and other variables such as sex, antibiotic consumption before admission, duration of symptoms from their onset till the time of admission and the presence of other indices such as fever, seizures, meningism and use of corticosteroids in the treatment regimen.The overall mortality rate in our study was 10% and the incidence of complications on discharge as 13.3%. In conclusion, on the basis of the results obtained, despite the use of advanced supportive systems for these patients and also modern broad spectrum antibiotics and appropriate diagnostic methods, no obvious change in factors affecting prognosis compared to two decades back has been seen. Likewise because of the absence of follow up of patients following discharge, it appears that further teaching is needed about this disease among students and residents besides creating specific centers to prevent this disease.