One of the most important problems of the surgical treatment of the hydatid disease of the liver is the remaining cavity of the cyst. Its evolution is mainly decided by the existence and the debit of a biliary fistula. During 10 years (1997-2006), 138 patients with 166 hydatid cysts of the liver were admitted and operated in our clinic. Among them, 57 cysts had a biliary fistula, found during the operation, while in 11 other patients the fistula became obvious 1 or 2 days after the procedure. The incidence of biliary fistulas (68 of 166 cases, which means 41%) is higher, due to the location of the cysts, mainly in the central parts of the liver. There were 44 (65%) low debit fistulas and 24 (35%) high debit fistulas. Our surgical attitude regarding the cavities with biliary fistulas has considerably changed; while between 1997-2000 an anastomosis with a Y or Omega jejunal loop was the most frequent technique, nowadays we use the external drainage of the cavity, associated to endoscopic sphincterotomy, for fistulas with large volumes (more than 300 ml/day) and/or persistent. Whenever it is possible, we practice the direct suture of the biliary fistula.