Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 47 11 2018 11 01 1644 1652 Qing WANG Dept. of Economic, School of Business, Dalian University of Technology, Panjin, Liaoning, China AND Dept. of Social Medicine and Maternal & Child Health, School of Public Health, Shandong University, Jinan, Shandong, China 2018 10 29 Background: The world is experiencing the biggest wave of urban growth in history. The association between urbanization and health at the global level, as well as the role of air pollution, has not been studied. We aimed to examine the effect of urbanization on global health and the role of air pollution. Methods: Unbalanced panel data comprising 3, 093 observations of 163 countries for 1990–2012 from the World Bank database was used. An infinite distributed lag model was applied to estimate the contemporary and long-term effects of urbanization on health outcomes measured by mortality, under-five mortality, infant mortality, life expectancy at birth(all; female; and male). Results: Urbanization was positively related to global health in the short term and long term. In the short run, 1% increase in urbanization was associated with reduced mortality, under-five mortality, and infant mortality of 0.05%, 0.04%, and 0.04%, respectively, as well as increased life expectancy of 0.01 year. The effects of urbanization were stronger for high-income countries. However, air pollution undermined the positive impacts of urbanization on health. Conclusion: Although urbanization leads to improved global health, air pollution undermines the positive effects of urbanization on health. Developing sustainable urbanization practices is crucial for addressing the challenges of pollution caused by urbanization.   https://ijph.tums.ac.ir/index.php/ijph/article/view/15144 https://ijph.tums.ac.ir/index.php/ijph/article/download/15144/6189