Of 1192 lung resections in patients with bronchogenic carcinoma since 1952, the early post-operative mortality averaged 3.9%, whereas during the last ten years, it was 2.6% of 730 lung resections, including 159 (22%) pneumonectomies, 76 (10%) bilobectomies, 492 (67%) single lobectomies and 3 (0.4%) partial lung resections. In the latter, 352 (48.2%) and 75 (10%) had airway obstructive failure of FEV1.0 less than 70% and 55%, respectively, and, 56 (7.7%) and 9 (1%) represented preoperative hypoxia of PaO2 less than 70 torr and 60 torr, respectively. The ratios of pneumonectomies in these, being similar to those with better lung functions, the perioperative mortality was also similar. Our previously reported indices preoperatively to prove ability to withstand curative lung resections, being supported by these data, we attempted in a certain limited group of patients, extendingly to clear patients with critically poor predicted pulmonary vascular reserve pf 710-930 dyne . cm-5 . sec/m2 for lung resections, resulting in six elevenths of over one year survival. One must extend benefit of lung resection to patients with coexistence of bronchogenic carcinoma and respiratory disorder apparently severe enough to preclude resection surgery by critical assessment of the predicted pulmonary vascular reserve after lung resection.