Primary sclerosing cholangitis was seen in only 7 of 6,494 biliary operations performed between 1948 and 1979. Fifteen more cases were seen in 1,467 biliary operations performed over a recent 5 year period. Surgery was directed primarily towards the differential diagnosis between cholangiocarcinoma and primary sclerosing cholangitis of the upper bile duct and the need for decompression (nine patients), accompanying gallstones (4 patients), and focal distal bile duct stricture with a question of cholangiocarcinoma (two patients). Invasive radiologic dilatation of the bile ducts was not possible in most instances. Two patients have had successful liver transplants and two more were pending at last follow-up.