Roux en Y hepatojejunostomy is the surgery of choice for bile duct repair. Anastomotical dysfunction after reconstruction has several etiopathologies. Besides technical factors, ischemia of the duct is responsible for late obstruction. Bile colonization with secondary stones and sludge can also be identified as a cause. An unusual cause of anastomotical dysfunction secondary to ascaris biliary infestation after biliary reconstruction is reported herein. The patient had intermittent cholangitis and eosinophilia. At operation, the worm was found obstructing the anastomosis.