Chronic obstructive pulmonary disease (COPD) has been targeted nationally as a "priority" condition for which multiple strategies are needed to improve outcomes. The absolute number of years lost to disability due to COPD exceeds the years of life lost due to premature death. There is strong evidence that pulmonary rehabilitation (PR) improves outcomes and is cost saving, but fewer than 2% of patients have access to these programs. New methods of PR are needed to increase access of patients with COPD to these established benefits. To address this gap we propose a novel physical activity self-management (PASM) program based on an evidence-based physical activity intervention designed to increase physical activity and quality of life. Key components of the program include tailored telephone counseling, a workbook, and computer-assisted telephone follow-up. Our specific aims are: 1) To implement a PASM program for patients with COPD. 2) To conduct an 18-month, randomized, controlled, single-blind trial comparing PASM (n=150) to usual care (UC) (n=150) to determine the effectiveness on functional performance and health status. 3) To determine the cost-effectiveness of the intervention. Follow-up data will be collected at 6, 12, and 18 months after start of the intervention. We will test the following two hypotheses: 1) Patients with COPD who receive PASM have clinically and statistically significant improvements in functional performance (i.e., Chronic Respiratory Questionnaire [CRQ] dyspnea domain and 6-minute walk) compared to patients who receive UC. 2) The PASM program is more cost-effective compared to the UC. The project addresses a major gap in the current management of COPD and may provide a novel, cost-effective strategy for improving functional performance and health status.