This study investigates the effects of State action on health in Brazil, considering social determinants of health. As a benchmark for population health outcomes, we adopted the Infant Mortality Rate (IMR). The research method is quantitative, with a quasi-experimental design. It is an ecological study using the 438 Brazilian health regions as unit of analysis. The data were collected from official government sources. The main statistical technique adopted was multiple logistic regression analysis. An outstanding aspect drawn from the results is that all the dimensions that measure state action used in this study presented statistically significant effects in decreasing the chances of a region being in a high IMR group, depending on the control variables included in the model. The only variable that presented a significant effect, considering all other factors of control, was the prenatal coverage indicator. Another important result was that the socioeconomic situation of the region had a substantial and significant effect on all models tested when the highest income level was compared to the lowest. Thus, for a possible reduction of health inequalities, the very determinants of social inequalities should be taken into account in addition to determinant or associated health factors. However, it should be noted that state action alone in the health area has the potential to act in determining the health conditions of the circumscribed population in each health region, even when considering the unequal distribution of socioeconomic factors in these territories.