In a retrospective study, based on 35 392 necropsies, 270 cases of severe acute pancreatitis (stage II or III) were compared with respect to diagnosis, survival time and cause of death. The proportion of correct clinical diagnoses made during life was 29.5% in cases of acute pancreatitis stage II, and 64.1% in severe acute pancreatitis stage III. The average survival time was 13 days. The most common cause of death was shock and intoxication. Most of the deaths in the first phase of the disease were due to pancreatogenic shock and enzyme intoxication. The considerable absorption of toxins from the necrotic tissue becomes a threat to life only after the first week of illness. There was a significant reduction in death rate on the sixth and seventh day of illness: the period from the fifth to seventh day of illness is, therefore, suggested as a most favourable time for any resection of necrotic pancreas tissue.