This study examines the effects of growing manufacturing employment on infant mortality across almost 200 Indonesian districts from 1985 to 1995, a time of rapid industrialization. Overall, we find no relationship between growing manufacturing employment in general and infant mortality. However, when the growth in manufacturing is concentrated in more polluting industries (as measured by the construction of a harm-weighted index of predicted emissions from manufacturing), there were economically and statistically significant increases in infant mortality. Finally, we consider a variety of potential causal channels that may change with industrialization (such as housing quality and access to health care) and whose change may help to explain the observed relationships. Although most of the various factors are correlated with infant mortality and the industrialization measures are correlated with changes in several factors, conditioning on these measures does not change our basic results.