Pulmonary function test is used as a guideline for safe pulmonary resection without complications. Usually FEVl lower than 1 liter is considered as a contraindication of lobectomy. Therefore, the curative operation of resectable lung cancer can not be performed in the case of poor pulmonary functions. Nowadays, there are some arguing points about the value of preoperative PFTs before the pulmonary resection. We performed a right pneumonectomy for stage H lung cancer in a patient with poor lung function test; FVC 2.17L, FEVl 0.97L, FEVl/FVC 44%, FEF 25-75％ 0.42L/sec, MVV 28L/min, TLC 5.18L, RV 2.99. During 4 months follow up, the patient had been tolerable. The follow up PFTs at postoperative 3 months 18 days showed up as follows; FVC 1.20L, FEVI 0.63L, FEVl/FVC 53%, FEF 25-75% 0.31L/sec, MVV 25L/min, TLC 3.80L, RV 2.33L.