Chronic obstructive pulmonary disease (COPD) is a common chronic illness that affects an estimated 210 million people worldwide, including 12 million people in the United States. National and international guidelines for treatment of COPD recommend use of certain medications, especially bronchodilators and corticosteroids, but the extent to which these are used appropriately is largely unknown. The objective of this study was to determine the extent to which pharmacotherapy for COPD is consistent with guidelines. Individuals with COPD (N = 2272), enrolled for at least 2 years in a large midwestern managed care organization, were identified from medical claims data. Medications dispensed in 2003 were examined using National Drug Codes from dispensation records. Quality indictors, developed from guidelines, focused on (1) use of bronchodilators, (2) use of inhaled corticosteroids (ICS) for patients with frequent exacerbations, and (3) use of systemic corticosteroids for acute exacerbation of COPD (AE-COPD). A total of 2272 subjects aged 45 years or older with a diagnosis of COPD were identified. Seventy-two percent of subjects with COPD received at least 1 bronchodilator; 64% of subjects with frequent prior exacerbations (> or =3 in the past year) received ICS; and only 51% of subjects with AE-COPD during the study year received systemic corticosteroids. Although most patients received 1 or more respiratory medications recommended by the guidelines, there were gaps in care including limited use of systemic corticosteroids for AE-COPD and ICS for patients with frequent exacerbations. Greater use of appropriate medications could lead to improved health for patients with COPD.