Concomitant pulmonary and liver hydatid cysts occur in 4% 25% of patients with echinococcosis. To evaluate the safety of a single-stage operation, experience with this procedure between 1992 and 2005 was reviewed. Of 152 patients who underwent surgery for pulmonary hydatid cyst, 30 had an additional hepatic cyst that was located on the upper dome of the liver in all cases. Pulmonary cysts were excised first via a posterolateral thoracotomy. After phrenotomy, the hepatic hydatid cyst was evacuated without capitonnage, and a Folly catheter was left in the cavity. Postoperative complications in the 30 patients with cysts in both locations included empyema in 2, bronchopleural fistula in 1, excessive biliary discharge in 3 and hemorrhage in 1. Hepatic hydatid cysts recurred in 2 patients. There was no hospital death. A single-stage posterolateral thoracotomy for extraction of pulmonary and liver hydatid cyst is an effective and safe surgical technique with few complications.