Between January 1981 and December 1990, 41 patients were operated on for hepatic hydatid disease, representing 18% of the overall surgery for liver disease performed in our institution during the same period of time. The mean age of the patients was 39.5 years (range 17-71 years), 24 were females and 17 males. The most common clinical sign was abdominal pain (59%) with 3 patients jaundiced at the time of admission. 2 patients suffered from acute rightsided pneumonia, one of them with a very important productive cough due to bronchial perforation of the hydatid cyst of the liver. One patient was admitted due to anaphylactic shock with collapse. For 14 patients (34%) the discovery of the disease was casual, either by clinical hepatomegaly or by X-ray investigations performed for other reasons. We performed 18 pericystectomies, 4 subtotal pericystectomies and 16 liver resections. Only 3 patients were treated by partial cystectomy with removal of the prominent part of the cyst. Several other surgical procedures were performed concomitantly, including 2 pulmonary lobectomies, 1 cystojejunostomy, and pericystectomies for other hepatic or extrahepatic localizations of hydatid cysts. Rupture of the cyst into the bile duct was diagnosed in 13 patients. One patient presented with a peritoneal rupture of the cyst and 2 patients had a fistula through the diaphragm into the pleural cavity. Our postoperative morbidity is acceptable (10 patients, 25%). A bilioma and a biliary leak were successfully treated by percutaneous drainage, a postoperative hemorrhage required surgical treatment, four patients experienced pulmonary complications and the three others minor wound abscesses.(ABSTRACT TRUNCATED AT 250 WORDS)