Caroli's disease is a rare congenital condition characterized by non-obstructive saccular or fusiform dilatation of larger intrahepatic bile ducts. Cholangitis, liver cirrhosis, and cholangiocarcinoma are its potential complications. The diagnosis of Caroli's disease depends on demonstrating that the cystic lesions are in continuity with the biliary tree which can be showed by ultrasonography, computerized tomography, endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography or magnetic resonance cholangiopancreatography. Treatment of Caroli's disease relies on the location of the biliary abnormalities. While localized forms confined to one lobe can be treated with surgery, liver transplantation is the only effective modality for diffuse forms. Although a rare disorder; Caroli's disease should always be considered in the differential diagnosis of chronic cholestasis of unknown cause. (C) 2007 The WJG Press. All rights reserved.