Data on all discharges from hospitals in Scotland have been recorded since 1961 as the Scottish Hospital In-Patient Statistics and examination of these data has permitted analysis of the incidence and mortality trends from acute pancreatitis. The number of discharges recorded has increased 11-fold in males from 69 patientslyear in 1961 to 750 patientslyear in 1985, and fourfold in females from 112 patientslyear to 484 patientslyear respectively. This increase has occurred particularly amongst young and middle-aged males (20-59 years) and in elderly females (over 60 years), the most marked increases occurring in the health boards of the 'central belt' area of Scotland. Mortality rate did not show a corresponding change, increasing only two-fold in males from 15 patientslyear to 30 patientslyear and in females from 29 patientslyear to 37 patientslyear. As a consequence the case mortality rate has fallen from 17.8 per cent over the period 1961-65 to 5.6 per cent over the period 1981-85. An apparent increase in the incidence of acute pancreatitis may be inferred from these data, much of which is thought to be due to improvedaccuracy in diagnosis.