The authors report a case of choledocal cyst extended to left and right hepatic ducts. An heterogeneous intracystic fluid, partial calcification of cystic wall, a slight positivity of echinoccosis serology in a patient from a highly endemic country erroneously led to diagnosis of hydatid cyst invading the left hepatic duct. The diagnosis of choledocal cyst was done on the resection specimen after left hepatectomy. A small patch of cyst wall with terminations of both right sectorial hepatic ducts was used for cysto-jejunal Roux-en-Y loop anastomosis. Peculiarities of this type of choledocal cyst are discussed.