Airway inflammation plays a vital role in the pathophysiology of chronic obstructive pulmonary disease (COPD). Chronic airflow obstruction, a hallmark of COPD, is a manifestation of an intricate combination of loss of elastic recoil of the lung, small airway disease, mucus hypersecretion, and airway wall thickening/contraction. Airway inflammation appears to contribute to all of these components.