Abstract This paper explores road construction’s unintended consequences on health. Drawing evidence from a large-scale road development program in Ethiopia, we investigate the impact of road construction on infant mortality. Along major routes, we find that an additional road increases the probability of infant mortality by 3 percentage points. The empirical evidence suggests that waste exposure associated with road construction is a likely explanation for our findings. A large set of robustness checks rules out confounding factors such as migration and urbanization, and alternative mechanisms such as traffic pollution.