Determination of preoperatibe pulmonary function is crucial in avoiding complications from pulmonary resection, especially pneumonectomy. Postoperative morbidity and mortality were correlated with the preoperative results of five widely used tests of pulmonary function in 40 patients who underwent pneumonectomy for bronchiectasis, pulmonary tuberculosis, and carcinoma of the lung. Factors analyzed following operation included 30-day mortality, the incidence of arrhythmia, the frepuency of respiratory complications, and the number of individuals requiring prolonged mechanical ventilation. There were statistically significant differences[p<0.001]in mean values among FVC, FEV1, FEV1/FVC and MVV. But the difference of the FEF25-75% was not statistically significant.