SUMMARY Duodenal calcium and magnesium concentrations after pancreatic stimulation were measured in 25 patients with and without pancreatic disease. The concentration of both ions was higher in those with pancreatic disease, and furthermore these patients showed a different secretory pattern. These findings may be relevant to the aetiology of pancreatitis and to pancreatic calcification, and might be of diagnostic value.Pancreatic calcification is often seen in chronic pancreatitis and it is accepted that the pancreatic inflammatory disorders can be associated with abnormalities of calcium metabolism. For example between 7 and 19% of patients with hyperparathyroidism have had pancreatitis (Mixter,