Cholestasis is acommon complication of hepatic hydatid cyst. We describe the various mechanisms of cholestasis in hepatic hydatid cyst as demonstrated by percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) in 16 patients. In our patients, cholestasi was the result of rupture or mechanical pressure of the cyst on the biliary system. Direct visulization of the bile duct, especially by PTC, provided precise definitions of the pathology, and aided the surgeon in his approach. There were no adverse reactions. All pre operative diagnoses were confirmed at operation.