This paper examines the effects of three large, coal-fired power plant closures on student absences and achievement in the Chicago area. We find that schools near the plants experienced a 7 percent reduction in absences relative to those further away following the closures. Math achievement in these schools increased following the closures, although our estimates are imprecise. Using data on wind, air conditioning, and magnet schools, we show that schools with higher baseline pollution exposure experienced the greatest gains from the plant closures. Our analysis of mechanisms suggests that health is an important channel through which air pollution affects absences.