Thirty-five patients with acute fulminant (hemorrhagic) pancreatitis, verified at laparotomy, were allocated to either pancreatic resection (18 patients) or peritoneal lavation (17 patients) therapy groups. Pancreatic resection was carried out by removing the distal pancreas well cephalad to the portal vein. For peritoneal lavation, two inlet silicone catheters were inserted at laparotomy around the pancreas and an outlet catheter was inserted in the lower abdomen, and the peritoneal cavity was thereafter lavated (1000 ml/hr) with a standard peritoneal dialysis fluid for 7 to 12 days (or until death if met earlier). In other respects, the postoperative care was similar, including intravenous fluids with total parenteral nutrition until oral intake of food was resumed, prophylactic antibiotics (tobramycin and clindamycin) and stress ulcer prophylaxis (cimetidine and antacids). In the resection group, four of the 18 patients (22.2%) died, while in the lavation group eight of the 17 patients (47.1%) died. The most common cause of death was septic complications with multiple organ failure, but one patient in each group died accidentally of airway complications. There was no difference in the incidence of septic complications (sepsis and/or intra-abdominal abscesses), but the incidence and severity of pulmonary and renal complications were greater in the lavation group. However, these complications accumulated to patients who ultimately died. Also, the need for reoperation was greater in the lavation group (20 reoperations/10 patients versus 12 reoperation/eight patients). Yet, the length of overall hospital stay was equal in the two groups. Six of the 14 survivors in the resection group developed diabetes, whereas none of the nine survivors in the lavation group got this complication. The results suggest that pancreatic resection is superior to peritoneal lavation in the management of acute fulminant (hemorrhagic) pancreatitis, decreasing mortality and affording smoother postoperative course. However, these benefits are gained at the expense of higher incidence of postoperative diabetes.