["Oxford Bulletin of Economics and Statistics, EarlyView. ", "\nABSTRACT\nThis paper examines the effect of Brazil's Family Health Program (Programa Saude da Familia, FHP) on cognitive skills (measured by test scores) of fifth‐grade students. We use biennial data from national exams between 2007 and 2015, and variation in the FHP implementation date across municipalities, birth cohort, and test year to identify the effect of the program on language and mathematics test scores. In municipalities in the North and Northeast regions, students exposed to FHP at or before birth score 0.72 points higher in language and 0.98 points higher in mathematics than those first exposed later, corresponding to 0.0194 sd and 0.0259 sd in intent‐to‐treat estimates. We further show that early exposure to FHP is associated with improvements in test scores in municipalities with lower income and limited access to basic public health infrastructure, such as access to running water and sewage, providing further evidence that the program benefitted economically disadvantaged municipalities the most. Heterogeneity analyses reveal no significant differences by student gender or mother's education, but important differences by race, as the program effects are concentrated among mixed‐race and Black students. Our findings are consistent with health‐related channels playing an important role, rather than measured parental engagement, although the precise mechanisms cannot be directly identified with the available data.\n"]