Background. Bilateral lung volume reduction is designed to improve pulmonary function in selected patients with severe emphysema by improving diaphragmatic and chest wall mechanics. Early results of lung volume reduction suggest significant improvement to selected patients with chronic obstructive pulmonary disease, some of whom might otherwise be considered for lung transplantation. The purpose of this review was to compare intermediate results of volume reduction with single and bilateral lung transplantation. Methods. Functional performance and survival after volume reduction were compared with single and bilateral sequential lung transplantation. After evaluation, patients were enrolled in a supervised intensive preoperative and postoperative program of pulmonary rehabilitation. Functional assessment, including pulmonary function tests, room air arterial blood gas analysis, and 6-minute walk distance, was obtained before the operation and 3, 6, and 12 months after the operation. Results. Thirty-three patients underwent volume reduction (mean age 57 years), 39 patients single lung transplantation (55 years), and 27 patients bilateral lung transplantation (49 years). Early mortality was 0, 1 of 39, and 2 of 25 and mortality at 12 months was 1 of 33, 4 of 39, and 4 of 25 in the volume reduction, single, and bilateral lung transplantation groups, respectively. At 6 months, mean forced expiratory volume in 1 second was improved by 79% (volume reduction), by 231% (single lung transplantation), and by 498% (bilateral lung transplantation) over preoperative values. Exercise endurance as measured by 6-minute walk distance increased by 28% (volume reduction), by 47% (single lung transplantation), and by 79% (bilateral lung transplantation) from baseline. At 6 months, all patients having single or bilateral lung transplantation and 26 of 33 patients having volume replacement were free of supplemental oxygen. Conclusions. Although single and bilateral lung transplantation result in superior lung function, volume reduction achieves satisfactory improvement of disabling symptoms early after operation while avoiding immunosuppression and transplant-specific complications. Our experience suggests that (1) volume reduction is a suitable alternative in selected patients eligible for transplantation; (2) volume reduction provides an earlier option for treatment in patients who may require transplantation at some future date; (3) volume reduction is the only surgical treatment available to the many patients who are not current or future transplant candidates. Conversely, in patients not suitable for volume reduction, transplantation remains the only choice for surgical therapy.