Pulmonary sequestration is often found in children with recurrent pneumonia, but is not rare in adults. During the last 6 years (1985-1990), 6 patients with pulmonary sequestration were surgically treated. One 40-year-old patient had an extralobar sequestration, and 5 patients ranging in age from 14 to 26 years had an intralobar sequestration. The patient with extralobar sequestration was asymptomatic. In cases of intralobar sequestration, 4 patients were symptomatic. All 6 patients had an abnormal chest roentgenogram. Preoperative arteriography revealed anomalous blood supply came from a systemic artery in 4 patients. All cases with intralobar sequestration had a lower lobectomy, and one case with extralobar sequestration had an extirpation. Even in cases without any symptoms, there was the possibility of a microscopic infection in the sequestrated lesion with the occurrence of later symptoms. Therefore, patients diagnosed with pulmonary sequestration should be considered for surgical resection.