An analysis is presented of 64 fatal cases of acute pancreatitis in the decade 1972-1981. In the same period altogether 2842 episodes of acute or relapsing pancreatitis were treated. The male/female ratio in the fatal cases was 49/15, with mean age 46.9/61.4 years. The mortality rate was 22% among patients with acute hemorrhagic pancreatitis and 2.3% among all patients. Of the patients who died, 23% had fewer than 3 Ranson signs, suggesting mild pancreatitis. The etiology of the disease was alcohol in 48% of the fatal cases, biliary disease in 16% and postoperative state in 17%. The study indicated two groups with high mortality rate--young men with a first attack of alcohol-induced pancreatitis and elderly patients with pancreatitis of biliary origin. Systemic complications arose in all patients, the most common being respiratory dysfunction (51%), anuria/uremia (33%) and intra-abdominal complications (31%). The most important causes of death were anuria (27%), respiratory dysfunction (22%) and gastric bleeding (13%).