A case of subcutaneous fat necrosis as the initial manifestation of an attack of acute pancreatitis is presented. The accompanying features of respiratory distress syndrome, leukemoid reaction, shock, pleural effusions, and arthritis due to necrosis of periarticular fat are described. Autopsy findings are pancreatic pseudocyst, serofibrinous peritonitis, pleuritis, and pericarditis and fat necrosis not only in the subcutaneous fat but also in the pericardial, pleural, mediastinal, mesenteric, retroperitoneal, and pericalyceal fat.