Pulmonary sequestration occurs when some disturbance produces a cystic mass of nonfunctioning lung tissue which lacks normal communication with the tracheobronchial tree. Between 1971 and 1985, pulmonary sequestration was diagnosed in 11 patients, ranging age from 3 to 29 years. All sequestration were intralobar type. Definitive diagnosis can only be obtained by aortography and/or surgical exploration in 10 cases. The other one was confirmed by pathologic examination postoperatively. The presenting complaints were mostly recurrent local pulmonary infection, but in 2 cases mediastinal mass with respiratory symptoms was presented, and cardiac murmur was only finding in one case. Preoperative diagnostic procedure revealed 3 associated anomalies which were funnel chest, right aortic arch, and pulmonic stenosis with vascular ring. Operative treatment for sequestration was lobectomy in 10 cases, and a segmentectomy in one. There was no operative mortality, but 3 complications [empyema, B-P fistula, post-op bleeding] which were controlled by subsequent operations or conservative measure. Aortography is strongly advocated not only for its diagnostic value, but for its preoperative localization of the aberrant vessels that are the major concern to the surgeon.