Acute pancreatitis is in the majority of patients a mild, self-limiting illness. Five to fifteen percent of the patients develop acute necrotizing pancreatitis, a severe illness with a high morbidity and mortality. Secondary infection of the pancreatic necrosis (infected pancreatic necrosis) is the main cause of death. Pancreatic necrosis is identified with a high accuracy by contrast-enhanced computed tomography. The differentiation between sterile and infected necrosis requires demonstration of bacteria or fungi isolated from the necrosis. Surgical treatment of a sterile necrosis remains controversial, but there is a tendency towards conservative non-operative treatment. Infected pancreatic necrosis is regarded as an absolute indication for surgery, untreated the mortality is approximately 100%. The aim of modern treatment is to remove the pancreatic necrosis continuously. This has successfully been done by the open packing method, with or without subsequent drainage. At present no randomized trials comparing the different treatment modalities are available. The question of prophylactic antibiotics still remains unanswered. For the present imipenem 0,5 g x 3 is recommended.