Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and mortality in both high- and low-income countries. While active cigarette smoking is the most important preventable risk factor globally, outdoor and indoor air pollutants can cause or exacerbate COPD. In high-income countries, historic air pollution events provide clear evidence that exposure to high levels of outdoor air pollutants is associated with increased mortality and morbidity due to COPD and related cardiorespiratory diseases. Studies in the last 20 years continue to show increased risk associated mainly with particulate matters, even at much lower levels. Populations in low-income countries are largely exposed to indoor air pollutants from the combustion of solid fuels, which contributes significantly to the burden of COPD-related diseases, particularly in non-smoking women. Effective preventive strategies for COPD may vary between countries, and include continued improvements in air cleaning technology, air quality legislation and dissemination of improved cooking stoves. A joint effort from both society and governments is needed for these endeavors.