Chronic Obstructive Pulmonary Disease (COPD) is manifested by chronic cough, sputum production, wheezing and, in later stages, dyspnea, poor exercise tolerance, and signs/symptoms of right-sided heart failure. Symptomatic COPD affects more than 5 percent of the adult population, is the fourth leading cause of death, and the twelfth leading cause of morbidity in the United States. In more than 80 percent of cases, cigarette smoking is causally linked to the development of COPD. Smoking status should be assessed in all adults, and smokers should be advised to abstain from tobacco. COPD is diagnosed in symptomatic individuals through spirometric testing that demonstrates irreversible airflow obstruction. Spirometry for case-finding diagnosis and management of all adults with persistent respiratory symptoms or having a history of exposure to pulmonary risk factors has been recommended in primary care settings for all current and former smokers as well as never smokers who have persistent respiratory symptomsor have history of exposure to other COPD risk factors. This report was prepared to provide objective evidence and recommendations to inform the work of the American Thoracic Society (ATS), in collaboration with the American Academy of Family Physicians, the American College of Physicians, and the American Academy of Pediatrics Spirometry Task Force in clarifying usage of spirometry as part of the management of COPD. A systematic literature review was undertaken to address four questions: 1. What is the prevalence of COPD and airflow obstructions in various adult populations as defined by: (1) spirometry and (2) clinical examination? 2. Can use of spirometry lead to increased smoking cessation rates? 3. Does the effectiveness of COPD-specific therapies to improve clinically relevant outcomes vary based on baseline severity or change in spirometry? 4. Is prediction of future COPD status based on spirometry, with or without clinical indicators, more accurate than prediction based on clinical indicators alone?