Introduction This paper is a review of our experience with severe acute pancreatitis at the University Hospitals of the State University of Iowa over a 20-year period, 1940-1960. The cases were selected upon the basis of history and physical findings indicating a severe illness and, in addition, by either high serum amylase levels or surgical or autopsy demonstration of severe acute pancreatitis. A total of 60 cases is in this series with a mortality of 29 (48.3%). Forth-two had their diagnosis substantiated either by operation during the acute illness or at autopsy. Of the remaining 18, the average amylase level was 1,419 Somogyi units, with the lowest level at 409 and the highest 5,330 units. Patients were not accepted for this series if the diagnosis was questionable, if the amylase level was below 400, or if their clinical findings were not those of a severe illness.* The entrance diagnosis in