Experimental acute necrotizing pancreatitis was induced retrogradely in dogs with sunflower oil injected intraductally. Then, a zipper was sutured into the abdominal wound. From the first postoperative day, three different treatments were started: first group: only conservative therapy was used; second group: removal of necrotized tissue and single peritoneal lavage were applied; and third group: the necrotic part of the pancreas was marsupialized into the stomach. Through the systematic opening of the zipper, the abdominal cavity could easily be explored and the temporal course of disease could be observed in all animals. During this regular procedure, the amylase concentration and the amount of peritoneal exudate were determined. The blood amylase and glucose levels were also measured. On the first postoperative day, the amylase level and the amount of peritoneal exudate were high in all groups. The dogs of the pancreatogastrostomized group showed a dramatic decrease of the exudate and the most advantageous temporal course of the blood amylase level. The survival rate similarly was advantageous in the pancreatogastrostomized group.