Liver hydatidosis, caused by the Echinococcus granulosus, commonly affects the liver and can lead to hepatic hydatid cysts. While many cases are asymptomatic or have mild symptoms, larger cysts can cause pain in the right upper quadrant, an enlarged liver, palpable mass, abdominal fullness, nausea, and vomiting. Complications, although seen in one-third of patients, can be severe and include cyst rupture, biliary colic, obstructive jaundice, cholangitis, acute pancreatitis, anaphylaxis, organ failure, and cyst infection. Cystobiliary fistula, intrabiliary rupture, is a serious complication, occurring in the biliary ducts of the liver and leading to jaundice, cholecystitis, cholangitis, liver abscess, pancreatitis, and septicemia. Conventional surgery for major cystobiliary fistula complications has had high morbidity and mortality rates. Endoscopic retrograde cholangiopancreatography (ERCP) has emerged as a valuable alternative, both for pre- and postoperative management of hepatic hydatid cyst patients with biliary complications. It is recommended for patients with postoperative adverse events and suspected cystobiliary fistula. However, the routine use of preoperative ERCP and prophylactic endoscopic sphincterotomy in patients with suspected minor cystobiliary communications remains unclear. The increasing use of magnetic resonance cholangiopancreatography adds to the debate on the necessity of preoperative diagnostic ERCP. In this chapter we review the role of ERCP in the diagnosis and treatment of cystobiliary fistula of hepatic hydatid cysts in the pre- and postoperative periods.