Choledochal cyst is defined as a cystic dilatation of the distal common bile duct protruding into the duo- denum. It is considered as the rarest congenital cyst of the biliary tract by 1.4%. We report a 46 years old woman who presented with recurrent jaundice associated with abdominal pain of 07 years duration. The liver function tests showed cholestasis. The abdominal scan and Biliary MRI revealed a dilatation of intrahepatic, pancreatic ducts and a dilatation of the common bile duct with a stenosis in its the lower part. The diagnosis of a common bile duct cholangiocarinoma was mentioned. The gastroscopy revealed a stenosed duodenal bulb not allowing us to perform an echo endoscopy and ERCP. An intraoperative cholangiography illustrating a cystic dilatation of the papillary region in which exist a separate protrusion of the choledochal and wirsung ducts. Therefore, we didn’t accomplish the cephalic duodeno-pancreatectomy and we decided to realize a partial resection of the papilla. The histolological examination proved the absence of any tumoral lesion and the presence of biliary mucosa layered the internal surface of the cyst. The patient is still asymptomatic after one year of the surgery.