Health disparities, defined as a significant difference in health between populations, are more common for diseases of the respiratory system than for those of other organ systems, because of the environmental influence on breathing and the variation of the environment among different segments of the population. The lowest social groups are up to 14 times more likely to have respiratory diseases than are the highest. Tobacco smoke, air pollution, environmental exposures, and occupational hazards affect the lungs more than other organs and occur disproportionately in ethnic minorities and those with lower socioeconomic status. Lack of access to quality healthcare contributes to disparities. The executive committees of the American Thoracic Society (ATS) and European Respiratory Society (ERS) established a writing committee to develop a policy on health disparities. The document was reviewed, edited, and approved by their full executive committees and boards of directors of the societies. This document expresses a policy to address health disparities by promoting scientific inquiry and training, disseminating medical information and best practices, and monitoring and advocating for public respiratory health. The ERS and the ATS have strong international commitments and work with leaders from governments, academia, and other organisational bodies to address and reduce avoidable health inequalities. Their training initiatives improve the function of healthcare systems and health equality. Both the ATS and the ERS support all aspects of this document, confer regularly, and act together when possible, but the activities to bring about change may vary because of the differences in the continents where the two organisations carry out most of their activities. The ATS and ERS pledge to frame their actions to reduce respiratory health disparities. The vision of the ATS and ERS is that all persons attain better and sustained respiratory health. They call on all their members and other societies to join in this commitment.