Over the past decades several epidemiological studies have been published reporting on incidence trends, hospital admissions, etiological factors and outcome of both acute and chronic pancreatitis. Over time, the incidence of acute pancreatitis has increased in the Western countries. Also, the number of hospital admissions for both acute and chronic pancreatitis have increased. These upward time trends possibly reflect a change in the prevalence of main etiological factors (e.g. gallstones and alcohol consumption) and cofactors such as obesity and genetic susceptibility. Acute and chronic pancreatitis are associated with significant morbidity and mortality and a substantial use of health care resources. Although the case-fatality rate of acute pancreatitis decreased over time, the overall population mortality did not change for both acute and chronic pancreatitis. This chapter will focus on recent developments in the epidemiology, aetiology, natural course and outcome of both acute and chronic pancreatitis.