The authors compared the clinical, electroencephalographic and CT evolution of 31 cases of brain hemispheric abscesses. The vital prognosis was largely improved by the introduction of the CT scan, as compared with previous series. The functional evolution was better in the group of patients receiving high dosage (15 cases) antibiotics and/or puncture (4 cases) in the case of a large lesion, than in patients whose abscesses were removed (12 cases). The CT scan confirmed this difference, with frequent atrophy after excision.