Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease responsible for a large human and economic burden around the world. Cigarette smoking is the main risk factor for COPD in the developed world, although other important risk factors include occupational exposures, air pollution, airway hyperresponsiveness, asthma, and genetic predisposition. In most of the world, COPD prevalence and mortality continue to rise in response to increases in smoking, particularly by women and adolescents. COPD is also an important cause of disability, and is linked to comorbid diseases, such as depression and cardiovascular disease, which adds to the large economic burden associated with this disorder. Better public health and medical interventions that target both the risk factors for COPD and look toward earlier intervention may decrease the growing public health impact of COPD.