A recent experience with a case of primary carcinoma of the cystic duct which is rare condition in biliary malignancies is presented. A 57-year-old man was admitted because of severe hypochondralgia. Laparotomy was performed after percutaneous transhepatic gallbladder drainage was carried out under a diagnosis of acute cholecystitis. As any stones were not detected in the gallbladder and a tumor in the cystic duct was suspected, bile duct resection and dissection of lymph nodes in the hepatoduodenal ligament were performed in addition to cholecystectomy. In postoperative pathological investigation, carcinoma of the cystic duct was proved. Carcinomas of the cystic duct often form small tumors, and such tumors are commonly detected only in the course of operation or the pathological examination of the specimen. In particular, in the case of cholecystitis without stones, preoperative examination and operation should be done with consideration of possible existence of carcinoma in the cystic duct.