We report the case of a 66-year-old man who presented with abdominal pain and jaundice. Cholangiographic examination done during percutaneous transhepatic biliary drainage(PTBD)revealed a middle common bile duct stenosis,20 mm in diameter,and a protruded lesion,2 mm in diameter,located in the lower common bile duct. Subsequently, a pancreaticoduodenectomy was performed since a common bile duct carcinoma was suspected. On Pathology, the circular, flat, diffuse tumor was found to be 23 mm in diameter and was located at the middle common bile duct ;this lesion had poorly and welldifferentiated tubular adenocarcinoma findings within the subserosa layer(ss). A circular,flat tumor that was 12 mm in diameter was located at the lower common bile duct ;in this lesion,a well-differentiated tubular adenocarcinoma within the layer fibromuscular (fm)was diagnosed. The two carcinomas were distant from each other, each included intramucosal carcinoma findings. The case was therefore diagnosed as synchronous double cancer of common bile duct carcinoma. To our knowledge, only one previous case of synchronous double cancer of the common bile duct has been reported in the Japanese literature to date.