A consecutive series of 614 operative cholangiograms was studied prospectively to determine the relationship of pancreatic-duct reflux to a previous history of acute gallstone pancreatitis. Of 53 patients who had previously had pancreatitis, 33 had pancreatic-duct reflux on their cholangiogram (62.3%), whereas, of 561 patients with no history of pancreatic disease, pancreatic-duct reflux was seen in only 82 (14.6%). In patients with a history of pancreatitis, reflux occurred into a wider pancreatic duct, at a greater angle between the bile and pancreatic ducts, and was associated with a longer functioning common channel. The wider cystic duct, wider common bile duct, and multiple small stones seen in patients with previous pancreatitis and pancreatic-duct reflux were suggestive of gallstone migration being associated with reflux. There was no correlation between pancreatic-duct reflux and the presence of choledochal calculi. Two patients developed recurrent severe pancreatitis after pancreatic-duct reflux of infected bile. Patients with gallstone pancreatitis appear to have an increased tendency for pancreatic-duct reflux that is mechanically facilitated by differences in the choledocho-pancreatic duct anatomy.