Ninety consecutive cases of brain abscess admitted to this center between 1964 and 1978 have been reviewed. The overall mortality has fallen in three consecutive 5-year periods from 42 to 21 to 9.7%. A number of factors seem to be responsible for this. Early surgical intervention was associated with the reduction in mortality between the first and second 5-year periods. Recognition of the significance and extent of cerebral edema, confirmed since computed tomographic (CT) scans have been available, led to a greater use of steroids during the last 5-year period, but the number of patients thus treated was too small to permit an assessment of any effect on mortality. There is no evidence to suggest a change in the natural history of the disease, and surgical management has not altered significantly. Experience with CT scanning in this center in the diagnosis of brain abscess is limited. It is therefore not possible no assess whether any improvement in mortality may have arisen from the early and accurate diagnosis obtainable with this technique. Improvement in culture technique has been of major importance, leading to a better understanding of the bacteriology of brain abscesses. This has allowed a more rational antibiotic program to be instituted, in particular the use of agents active against obligate anaerobes.