Primary cystic duct carcinoma is a rare condition, for which preoperative diagnosis is difficult. We herein report a case of early primary carcinoma of the cystic duct, which was diagnosed preoperatively using endoscopic ultrasonography and endocholangioscopy. A 76-year-old man was admitted to our hospital with epigastric pain and liver dysfunction. Endoscopic ultrasonography revealed a cystic duct tumor, in diameter of 2.2 cm, which extended to the common bile duct. Endocholangioscopy revealed a well movable papillary tumor at the origin of the cystic duct. The patient underwent cholecystectomy and excision of the extrahepatic bile duct and lymph node. Histological findings confirmed the diagnosis of early papillary adenocarcinoma of the cystic duct.