With the development of antenatal diagnosis of pulmonary sequestrations, we were impelled to define more accurate perinatal operative indications for this anomaly.Fourteen children, 110 boys and 4 girls with pulmonary sequestrations were followed at the Pediatric Surgery Service in Strasbourg, during the last 6 years. Twelve underwent surgery. In eleven children, antenatal ultrasound (US) had established the diagnosis between the twentieth and the thirty-third weeks (average = 26 weeks) of intrauterine life. Nine of these children were operated. Two fetuses necessitated intrauterine treatment. One of them 1 suffered from a voluminous sequestration larger than one hemithorax, with associated diaphragmatic eversion, mediastinal deviation, hydrothorax, ascitis and hydramnios. Three successive paracentesis of ascitic and amniotic fluid on the 20th, 27th and 31st weeks allowed to continue pregnancy until term at 37 weeks. In the other fetus 2 , we noted a mass larger than one hemithorax with homolateral hydrothorax successfully evacuated by a pleuro-amniotic shunt placed on the 30th week. An absolute or relative regression of the thoracic ma~s size was observed in six patients. We were able to verify the systemic blood supply in 4 cases. At birth, the definite diagnosis of pulmonary sequestration was established preoperatively by MRI (9 cases), and by doppler-US. These two noninvasive diagnostic examinations permitted to demonstrate the presence of a systemic blood supply to the sequestration. Operative thoracoscopy was endeavored in four cases, but in two patients, the presence of dense pleuroparietal adhesions kept us from further endoscopic gestures and required conversion to thoracotomy. Pleural synechiae were either secondary to pleuro-amniotic shunting or to previous abscess formation within the mass. In one child, thoracoscopy revealed the intradiaphragmatic site of the sequestration, with a split diaphragm. Lastly, the non negligible size of the systemic blood supply to the mass, its intralobar site, and the easy bleeding caused by thoracoscopic gestures made us abandon the endoscopic technique for the excision of these richly vascularized malformations. Seven sequestrations were located in the