Between 1983 and 1988, 22 patients with brain abscess were admitted to our neurosurgery department; 2 patients deeply comatose on admission and who died on the first day were excluded from this study. Treatment consisted of needle aspiration of the abscess and antibacterial therapy initially using a broad-spectrum antibiotic later replaced, in all cases, by an antibiotic found to be active in vitro against the organism(s) isolated. The portal of entry was eradicated as early as possible. The duration of antibiotic therapy was determined according to the changes observed on computerized tomography images classified as cavitary, nodular, hypodense or normal. Nodular images were taken as reflecting an inflammatory state in the healing process, and hypodense images as sequelae, so that antibiotics were withdrawn in patients with such images. Altogether, 62 per cent of the patients received antibiotics for 60 days and 95 per cent for 90 days. There was no recurrence. In some patients with deep or, chiefly, multiple abscesses, treatment was pursued. In any case, antibiotics should not be given for more than 90 days if the initial treatment has proved effective, since cure is achieved in 45 to 60 days on average.