From July 1, 1974, to December 31, 1990, 2340 patients who underwent pulmonary resection were evaluated by comprehensive analysis of pulmonary function. Pulmonary function test criteria for resection were (1) pneumonectomy: forced expiratory volume in 1 second greater than 2 L; forced expiratory flow rate from 25% to 75% greater than 1.6 L; maximum voluntary ventilation greater than 55%; (2) lobectomy: forced expiratory volume in 1 second greater than 1 L; forced expiratory flow rate from 25% to 75% greater than 0.6 L; maximum voluntary ventilation greater than 40%; (3) wedge or segmental resection: forced expiratory volume in 1 second greater than 0.6 L; forced expiratory flow rate from 25% to 75% greater than 0.6 L; maximum voluntary ventilation greater than 35%. Split perfusion lung scan and Reichel exercise stress testing were utilized as indicated. When these values of pulmonary function have been applied, a more precise method of selecting patients for various types of pulmonary resection has resulted in a lower mortality while denying operation to less than 1% of the patients who are considered for surgical resection.