A retrospective study was performed to review the clinical features and outcome of 39 episodes of pneumococcal meningitis in 36 adult patients over a 12-year period. Overall mortality was 33.3%. Only a few of the deaths were directly related to the central nervous system disease and most of them were due to cardiorespiratory failure. Univariate analysis showed that death was more likely to occur in patients with advanced age, an absence of neck stiffness, a high pulse rate, an associated pneumonia, internal complications, or a long duration of the disease (greater than 7 days) before treatment was started. Patients who died had a higher erythrocyte sedimentation rate and serum bilirubin level and a lower serum sodium level than those who survived. Discriminant analysis showed the development of internal complications to be the strongest predictive factor of a poor outcome of illness. Two other important predictors of a poor outcome were the absence of neck stiffness and associated pneumonia. The history of a skull fracture or head surgery was significantly correlated with a better than average prognosis. The incidence of sequelae in survivors at the time of discharge amounted to 72%. None of the clinical features were significantly correlated with the development of sequelae, except a higher cerebrospinal fluid protein content.