Emphysema and other forms of COPD are not only common, but also have a poor prognosis. Mortality with severe COPD may be as high as 60% at 5 years and is associated with a significant degree of disability and cost to the health-care system. Building on Dr. Otto Brantigan's experience in the 1950s, when multiple-wedge resections of emphysematous lung were performed to decrease lung volume, thereby improving airflow and reducing hyperinflation, recent investigators, utilizing improved surgical and anesthetic technique, have redeveloped a surgical approach to the treatment of emphysema. The operations used to treat emphysema include excision of large bullae (bullectomy) and resection of diffusely emphysematous lung and are variously known as lung volume reduction surgery (LVRS), pneumectomy, and reduction pneumoplasty. These operations aim for a 20 to 30% reduction in lung volume and may be performed by stapler or laser resection, or both. The mechanisms of benefit have been attributed to enhanced elastic recoil, correction of ventilation perfusion mismatch, improved efficiency of respiratory musculature, and improved right ventricular filling. Questions that remain to be answered include duration of benefits, safety, and cost of LVRS. The National Heart, Lung, and Blood Institute and the Health Care Financing Administration have responded to the demand for more access to and information about LVRS by organizing both a national registry and controlled clinical trial of these procedures over a 7-year period. This multicenter trial intends to enroll patients with end-stage emphysema to compare methods of bilateral LVRS to maximal medical therapy.