No deaths have occurred among 20 consecutive patients with intraparenchyma brain abscesses treated at the University of California, San Francisco, since computerized tomographic (CT) brain scanning became a routine diagnostic procedure (study period: July, 1974, to June, 1977). These patients have been compared to 18 consecutive cases treated without benefit of CT analysis (January, 1970, to June, 1974) in order to determine the factors responsible for the recently improved prognosis. The mortality rate was 44% for all cases and 36% for all operated patients treated before the availability of CT. Similar morbidity (about 33%) was seen in survivors from both series. No significant differences in the two groups were noted with respect to patient population and antibiotic or corticosteroid therapy. Among the factors that may have contributed to the improved results for patients diagnosed with CT are: less frequent occurrence of multiple abscesses, fewer patients with poor preoperative clinical status, and a greater incidence of total abscess removal. In addition, CT scanning provided more accurate diagnosis and localization of abscesses and aided in the rapid detection of postoperative complications that probably accounted for six out of eight deaths in the earlier series. Serial CT studies provide a means to optimize the timing for surgical intervention and plan appropriate medical therapy. It is noteworthy that two patients have been followed by serial CT scans to non-surgical cures.