Between 1968 and 1979 650 patients in the Bristol clinical area suffered 737 attacks of acute pancreatitis. Sex distribution was approximately equal and mean age was 60 years. Comparison with the previous decade shows an increase in mean annual incidence of first attacks from 53.8 to 73.0 cases per million population. Case mortality was unchanged at 20%. In no less than 35% of fatal cases the diagnosis was first made at necropsy. Gall stones were detected in 50% of first attacks, predominantly in women. The proportion of alcoholics (8% overall) increased three-fold during the period of the study. In 23% of cases no aetiological cause was identified. Eighty patients suffered 99 recurrent attacks of acute pancreatitis, with a mortality rate (12%) that was not significantly lower than that of the first attack. Neglected gall stones accounted for 51% of these subsequent attacks.