The paper estimates the effect of SO 2 pollution on infant mortality in Germany, 1985–2003. To avoid endogeneity problems, I exploit the natural experiment created by the mandated desulfurization at power plants and power plants’ location and prevailing wind directions, which together determine treatment intensity for counties. Estimates translate into an elasticity of 0.07–0.13 and the observed reduction in pollution implies an annual gain of 826–1460 infant lives. There is no evidence for disproportionate effects on neonatal mortality, but for an increase in the number of infants with comparatively low birth weight and length.