For study the influencing factors to the complication after pneumonectomy, authors performed retrospective analysis in 33 patients managed surgically from February 1985 to February 1994 in the Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital.Among 33 patients, the underlying diseases were distributed 15 patients[45.5% pulmonary tuberculosis, 14[42.% lung cancer and 4[12.1% bronchiectasis. Numbers of complication according to the underlying disease after pneumonectomy were 8 in pulmonary tuberculosis, 2 in lung cancer and 1 in brochiectasis. Study was analyzed on age, sex distribution, etiology of underlying diseases and operated sides contributing to the complication. The results were characterized that the rate of occurrence of complication after pneumonectomy was not affected by age, sex and operated side differences but affected by the underlying disease.The development of complication after pneumonectomy in patients with pulmonary tuberculosis revealed statistically borderline significance comparing to the others[p=0.07 .