Background: A retrospectiye study was done for understanding morbidity and mortality after major lung resection. Material and Method: From June 1994 to August 1998, 203 patients received major lung resections for various causes. There were 142 males and 62 females with a mean age of 47.5 years. Initial complains were cough in 47.8%, sputum in 33.0%, hemoptysis or blood-tinged sputum in 23.2%, dyspnea in 18.2%, chest pain in 15.3%, weight loss in 10.8%, fever and chill in 4.9%. There were no complaints in 5.9% of the total patients. The underlying diseases were lung tumor(102 cases/50.2%), bronchectasis(28 cases/13.8%), aspergillosis(24 cases/1.8%), tuberculosis(20 cases/9.9%) and others (29 cases/66.5%) and pneumonectomy(68 cases/33.5%). The postoperative complications were classified as : empyema, BPF, respiratory problem, persistent air leakage over 7 days, arrhythmia, ventilator applied over 24 hours, bleeding, wound infection and chylothorax. The postlobectomy complications were revealed as follow: empyema(3.7%), BPF(2.2%), respiratory problem(5.2%), persistent air leakage over 7days(8.9%), arrhythmia(2.2%), ventilator applied over 24 hours(2.2%), bleeding(1.5%), wound infection(2.9%), chylothorax(0.7%). The postpneumonectomy complications were revealed as follow : empyema(5.9%), BPF (5.9%), respiratory problem(17.6%), persistent air leakage over 7days(0%), arrhythmia(5.4%), ventialtor apply over 24 hours(7.4%), bleeding (7.4%), wound infection(2.9%) and chylothorax(1.5%). Reoperation was done in 8 cases (4.0%). There were 5.8% operative mortalities in pneumonectomy and 0.7% in lobectomy.