The exocrine pancreatic function was studied in 460 patients suffering from dyspepsia (defined as abdominal pain, chronic diarrhoea, and/or weight loss) by measuring the duodenal concentrations of amylase and lipase after a test meal (Lundh test). In 159 of the patients (35 per cent) a reduced pancreatic function was found. In 143 out of these a diagnosis of possible or verified chronic pancreatitis was made. In about half of these 143 patients, the diagnosis chronic pancreatitis was clinically unexpected. Consequently, chronic pancreatitis is to be suspected as a cause of dyspepsia when more usual causes have been excluded.