The reported mortality due to pancreatic abscesses after acute pancreatitis has been 30 to 50%, a statistic that has remained unchanged for decades. This is a report of 45 patients treated over 10 years, showing a dramatic improvement in survival during that period. They represent 2.5% of admissions at the Massachusetts General Hospital for acute pancreatitis. The identifiable antecedents included alcohol (38%), gallstones (11%), and surgical trauma (16%), or were unknown in 24%. Computerized tomography (CT) was clearly the best means of specific diagnosis (unequivocal evidence in 74%, suggestive in 21%). Treatment in 44 patients was surgical debridement and catheter drainage, and in one it was resection of the pancreatic head. Multiple abscesses were present at the first operation in 21 patients. Seven had second drainage procedures for additional abscesses. In the first 5 years (1974-1978), 10 of 26 patients died (38%). In the second 5 years (1979-1983), one of 19 died (5%) (p less than 0.01). Postoperative complications (84%) included wound hemorrhage (9 of 26 vs. 1 of 19), systemic sepsis (7 of 26 vs. 1 of 19), pancreatic fistula (14/45, 13 of which closed spontaneously), colonic perforation (4), duodenal perforation (2), and gastric perforation (1). The causes of death were renal and respiratory failure with sepsis (7), hemorrhage (3), and pulmonary emboli (1). Analysis of the findings shows in the second 5-year period more frequent use of CT to certify the diagnosis of pancreatic abscess earlier, a more aggressive attitude producing earlier surgical intervention, and more extensive drainage and debridement of associated necrotic tissue. Transcatheter arterial embolization was used successfully to control postoperative hemorrhage from the abscess cavity. CT-guided percutaneous catheter drainage was used occasionally for drainage of recurrent abscesses. Neither open packing of major pancreatic abscesses nor lavage of the abscess cavity, as recently advocated, was necessary.