The results of changes in dyspnea and pulmonary function are reported in 27 emphysematous patients followed up for about 10 years after removal of giant bullae, which occupied at least 50% of a hemithorax. In 10 patients bilateral bullectomy was done. The spirographic improvement depends on the type of bulla. Resection of bullae at open communication with the bronchial tree resulted predominantly in improvement of forced expiratory volume as a percentage of vital capacity, whereas after closed bullae were resected, the increase in vital capacity was most apparent. Dyspnea lessened in all patients. Seven older patients died of ventilatory insufficiency. Preoperatively they were clinically and functionally severely disabled. They improved markedly after bullectomy, and their mean survival time was more than 7 years. In all 27 patients improvement of dyspnea and pulmonary function lasted several years and only gradually returned to preoperative values and beyond. No giant bullae recurred in the observation period; neither was there an accelerated progression of the emphysematous process. Our present selection criteria, based on previous experience, are as follows: giant bullae occupying at least 50% of a hemithorax, definite displacement of adjacent lung tissue, exclusion of the presence of vanishing lung syndrome, and absence of chronic purulent bronchitis.