A total of 21 patients with pulmonary sequestration who had undergone surgical treatment were reviewed at the department of thoracic and cardiovascular surgery of catholic university medical college from May 1983 through May 1993. The pulmonary sequestration was intralobar in 19 patients, and extralobar in 2 patients. There were 17 woman and 4 man ranging of age from 17 months to 48 years with a mean age of 21.3 years. Clinical manifestations were varied from no symptom[3 cases to recurrent pneumonia[15 cases , and hemoptysis[3 cases . Preoperative diagnosis was correct in only 6 cases[29% of the 21 patients of pulmonary sequestration . The left lower lobe[11 cases is most often affected in intralobar sequestration. The aberrant artery in intralobar sequestration originated in 13 cases[68% of 19 cases from descending aorta. 15 of the 19 patients of intralobar type underwent lobectomy. The extralobar sequestration[2 cases were simply excised. There was no mortality and no complication.