Ambient air pollution is a major problem in many countries of the developing world. This study examines the relationship between long-term exposure to air pollution and COVID-19-related deaths in four countries of Latin America that have been highly affected by the pandemic: Brazil, Chile, Colombia, and Mexico. Relying on historical satellite-based measures of fine particulate matter concentrations and official vital statistics, our results suggest that an increase in long-term exposure of 1 μg/m3 of fine particles is associated with a 2.7 percent increase in the COVID-19 mortality rate. This relationship is found primarily in municipalities of metropolitan areas, where urban air pollution sources dominate, and air quality guidelines are usually exceeded. Our findings support the call for strengthening environmental policies that improve air quality in the region, as well as allocating more health care capacity and resources to those areas most affected by air pollution.