Pulmonary rehabilitation is an established treatment for patients with chronic lung disease. Benefits include improvement in exercise tolerance, symptoms, and quality of life, with a reduction in the use of health care resources. As an adjunct to surgical programs, such as lung volume reduction surgery, pulmonary rehabilitation plays an important role not just in preparing patients for surgery and facilitating recovery but also in selecting patients and ensuring informed choices about treatment options after optimal medical care. In the National Emphysema Treatment Trial (NETT), subjects completed 6-10 weeks of comprehensive pulmonary rehabilitation before randomization and continued rehabilitation throughout the trial, both at home and with intermittent supervision at either an NETT center or an NETT-certified satellite center. Sessions included a combination of upper and lower extremity exercise, education, and psychosocial support. Before randomization, pulmonary rehabilitation resulted in highly significant changes in exercise capacity, dyspnea, and quality of life. As expected, improvements were significantly greater in those without prior rehabilitation experience. Results for patients completing rehabilitation at satellites were similar to those at NETT centers. Prerandomization pulmonary rehabilitation had a significant effect on outcome after lung volume reduction surgery. NETT identified subgroups with differential outcome by treatment (surgical vs. nonsurgical), defined in part by postrehabilitation maximum exercise capacity. Overall, NETT demonstrated the effectiveness of pulmonary rehabilitation in improving function, symptoms, and health status in a large cohort of patients with advanced emphysema treated in a cross-section of programs in the United States.