The authors report their experience with 6 patients requiring liver transplantation who suffered with liver infestation by Echinococcus granulosus. One patient presented with acute Budd-Chiari syndrome because obstruction of hepatic veins was produced during the first operation; the other 5 patients received liver transplants for terminal chronic liver disease (2 secondary sclerosing cholangitis, 2 secondary biliary cirrhosis, and 1 postnecrotic cirrhosis of the liver). All the patients had been operated previously on for hydatidosis and were at the end of liver functional disorder. Some of the patients had undergone many operations, making the transplantation procedure even more difficult. One patient required a second transplant for primary graft failure; he died 40 days later from cerebrovascular accident. Another patient died 7 months after transplant from pulmonary embolism. The other 4 patients are alive and in optimal condition 37-65 months after transplantation. Hepatic hydatidosis--in principle, a benign disease--can cause hepatic complications that eventually require liver transplantation. The transplantation procedure is more difficult than usual in these cases. Although postoperative complications are frequent, most patients achieve prolonged survival and a good quality of life.