Objectives. To investigate the effects of coal-fired power plant closures on zip code-level rates of emergency department visits for asthma-related conditions among 0- to 4-year-old children in Chicago, Illinois.Methods. We used data on wind, population, PM2.5 (particulates measuring ≤ 2.5 µm in diameter), and zip code-level rates of emergency department visits for asthma-related conditions among 0- to 4-year-old children between 2009 and 2017 in Chicago. The difference-in-differences research design compared rates of emergency department visits in zip codes near 3 coal-fired power plants before and after their closures to rates in zip codes farther away during the same time period.Results. We found that emergency department visits for asthma-related conditions among 0- to 4-year-old children decreased by 12% in zip codes near the 3 coal-fired power plants following their closures relative to rates in zip codes farther away during the same period. The crude and age-specific rates of emergency department visits decreased by 2.41 visits per ten thousand inhabitants and 35.63 visits per ten thousand children aged 0 to 4 years, respectively.Conclusions. Our findings demonstrate that closing coal-fired power plants can lead to improvements in the respiratory health of young children.