A retrospective review of 52 cases of neonatal meningitis diagnosed and treated at the Hospital for Sick Children, Toronto, was undertaken to determine which clinical or laboratory features were useful in predicting survival. Escherichia coli and group B streptococci were the most common bacteria isolated. Ventriculitis, cerebritis and arteritis were seen at autopsy with either gram-positive or gram-negative infection. Features associated with a good prognosis for survival were (a) peripheral neutrophil count greater than 2,000 x 10(9)/L; (b) normal platelet count or estimate (more than 100 x 10(9)/L), (c) birth weight greater than 2500 g and (d) age at the time of diagnosis more than 1 day. Information on all four features was available for 44 newborn infants. Of those with three or four of the features 87% survived, while of those with one or two features 14% survived. The overall mortality was 48%. The features outlined are useful in determining the severity of disease and therefore may alert the attending physician to the need for more intensive therapeutic and supportive care.