The mortality rate has decreased in severe acute pancreatitis as a result of advances in critical care technologies and of a more restrictive use of early surgical treatment. Formal pancreatectomies and early surgical removal of necrotized pancreatic tissue have a high mortality rate (50 p. cent) and do not prevent the secondary development of intraabdominal abscesses. Conversely, when the operation consists in removal of an abscess or of an area of infected necrosis, the mortality rate is under 20 p. cent. CT scan-guided percutaneous aspiration is useful for the diagnosis of infection, providing a bacteriologic diagnosis in over 90 p. cent of cases and thus avoiding unnecessary laparotomies in uninfected patients.