There is no one operative treatment for acute pancreatitis. Surgery is indicated to resolve diagnostic uncertainty and perhaps to modify the early course of 1 gallstone pancreatitis. Peritoneal lavage is useful in reversing early-phase systemic circulatory effects mediated by toxins in the ascitic fluid, but does not modify the underlying pancreatitis. When pancreatitis progresses to pancreatic and peripancreatic necrosis, the ultimate outcome is determined by a) the amount of necrosis, b) the extent of extrapancreatic necrosis, and c) bacterial contamination of necrosis. The amount of pancreatic regional necrosis that can be safely observed for healing is unknown; large collections tend to become infected secondarily and thus should be evacuated. Computed tomographic scanning is the best current means of detecting pancreatic necrosis and abscesses. Only percutaneous aspiration can reliably differentiate sterile from infected collections. As sepsis is the most common cause of death in acute pancreatitis, adequate surgical drainage is essential, while antibiotic therapy is only adjunctive. Aggressive treatment directed at the two principal causes of death, early-phase shock and late-phase sepsis, should reduce mortality to about 1% overall and to about 5% in cases complicated by regional necrosis and sepsis.