From January 1976 to December 1990, 495 cases of hydatid cyst of the liver were treated by resection of the cyst wall. The mean age of the patients was 42 years with a female predominance (71% of cases). Confirmation of the diagnosis was essentially based on ultrasonography. At operation, the hydatid cysts were located in the right lobe of the liver in 83% of cases. The hepatic dome (segments VII + VIII) was involved in 52% of cases. After resection of the cyst wall, biliary tract lesions required common bile duct drainage with a Kehr drain in 50 cases, transcystic drainage in 22 cases and cysto-biliary disconnection in 22 cases. In every case, drainage of the residual cyst cavity was performed by a two-way catheter. Seven deaths were recorded in this series, including one from anaphylactic shock associated with intracystic injection of formalin, 3 from bronchopulmonary complications, 2 from subphrenic abscesses and 1 after surgical revision for evisceration on the 5th day. The postoperative morbidity and, consequently, the hospital stay depended on the condition of the pericystic tissues. The mean hospital stay was 12 days in the case of soft pericystic tissues and 32 days in the case of fibrotic and calcified pericystic tissues. Due to the benign nature of hydatid cysts of the liver, the authors emphasise the value of resection of the cyst wall which carries a lower operative risk and which can be performed by most surgeons.