From 1971 to 1987. 32 patients with acute necrotizing pancreatitis were treated: 26 with the Lawson procedure—closed-tube drainage of the lesser sac, cholecystostomy, gastrostomy, and jejunostomy (group I)—and 6 with the open treatment, consisting of packing of the lesser sac with gauzes and frequent reexplorations (group II). Retrospectively, the effect of both treatment regimens was judged in relation to mortality and morbidity. In group I 13 patients (50%) died, all as a result of sepsis and multiple organ system failure, and 7 (26%) had to be reoperated on because of residual abscesses. In group II none of the patients died, and no residual abscesses were found. It is concluded that the open treatment of acute necrotizing pancreatitis offers optimal drainage of the peripancreatic area, thereby preventing ongoing inflammation, abscess formation, and multiple organ system failure.