This study evaluates the effect of the long acting somatostatin analogue octreotide on biochemical and clinical parameters of endoscopic retrograde cholangiopancreatography (ERCP) induced pancreatitis. Altogether 245 patients were randomised to receive either octreotide or isotonic saline. Octreotide (100 micrograms) was administered intravenously five minutes before ERCP and subcutaneously 45 minutes after ERCP. There were no significant differences in the median serum amylase and lipase activities at baseline, eight, and 24 hours after ERCP. Five patients (2%) developed clinical pancreatitis--three in the octreotide and two in the placebo groups. Excluding patients who developed pancreatitis, 43 (18%) developed abdominal pain after ERCP--21 in the octreotide and 23 in the placebo groups. There were no significant differences in the median serum amylase and lipase values between the treatment groups. None of the 52 patients who had therapeutic interventions developed pancreatitis. This study suggests that octreotide may not protect against ERCP induced pancreatitis.