In a group of 343 consecutive patients under 36 months of age with acute purulent meningitis, survival rates were encouraging but neurologic sequelae were disturbingly frequent. Fifty-five infants had subdural collections during the acute phase of their disease. An attempt was made to evaluate the prognostic significance of these. It appears clear that the frequency and severity of neurologic sequelae are related to the presence of early subdural collections, but these could not be specifically correlated as to volume, character, on time at which they occurred. Subdural collections are most frequent in the youngest patients, for whom early recognition of meningitis may be difficult or delayed. It is assumed, but not proved, that factors similar to those responsible for production of the subdural collections also caused many of the evidences of brain damage that appeared concomitantly or developed later.