In severe necrotizing pancreatitis, the retroperitoneum is the main site both of autodigestion and of the production of toxins. With the aim of removing necrotic tissues and active enzymes from the retroperitoneum, we developed a surgical approach based on a wide exposure of the pancreas and on the insertion of multiple drainages with postoperative irrigations with hypertonic solutions and antiproteases. We treated 191 patients, and our results correlated with the timing of the operation. The operative mortality rate ranges from 8.1 in patients undergoing our procedure within 48 hours from the onset of the disease to 28.4 per cent when the operation was delayed for more than 96 hours. Our technique is detailed and the indications as to the timing of surgical treatment in instances of pancreatitis are discussed.