Forty cases of hemolysis (drop of hematocrit greater than 12%/12 h) were retrospectively analyzed for hyperamylasemia and pancreatic complications. In 15 subjects the serum amylase level was greater than 360 U/l, i.e., three times the normal range, in ten the amylase level exceeded 900 U/l. Excluding patients in circulatory shock and/or hepatic coma, acute pancreatitis as defined by an elevation of serum amylase and clinical signs (epigastric pain) was present in four, with additional ultrasound findings (pancreatic swelling) and/or laparatomy/postmortem findings in a further six subjects (total ten patients = 25%) with various causes of hemolysis: autoimmune hemolysis 2, microangiopathic hemolytic anemia 2, toxicemia, G-6-PDH deficiency, septic abortion, malaria, Wilson's disease, and hypophosphatemia, one case each. In all subjects acute renal failure and in seven an activation of intravascular coagulation was seen. Three patients died (33% vs 47% of all hyperamylasemic patients and 46% of the whole group), but none of the deaths was attributed to pancreatitis. Pancreatic postmortem findings were diffuse edema and patchy parenchymal necrosis in two cases and petechial bleeding in one case. We conclude that acute pancreatitis is a complication of massive hemolysis, occurring at a prevalence of above 20%. It may progress from diffuse edema and inflammation to focal necrosis, rarely if ever to gross hemorrhage, and does not contribute to the high mortality of massive hemolysis. Back pain in hemolysis might originate from the pancreas rather than from the kidneys.