We analyze changes in child mortality in Vietnam during four decades of profound changes in the countrys political, socio-economic, and health care conditions. Our data and econometric models allow for a difference-in-differences approach to estimate the impact of the Popu- lation and Family Health Project (PFHP), one of several health pro- grams that have been implemented. We find strong improvements in overall mortality rates, although large regional differences persist. About half of the regional disparities can be attributed to differences in education and fertility-related behaviors. We find no evidence of a direct causal impact of the PFHP program on mortality rates.