Biliary obstruction of uncertain aetiology in a 69-year-old women led to a cholecystectomy and exploration of the bile tract: a nearly complete cast of the hepatic ducts and intrahepatic bile ducts was extracted. Histological examination of the gall bladder and liver biopsy failed to provide a diagnosis, but a bile duct biopsy taken at the time of an endoscopic retrograde cholangiography revealed the diagnosis of papillomatosis. This disease has a poor prognosis because there is no known cure.