In this review, we will investigate the pathways linking education and health to understand why education appears to improve health in some settings or among certain populations, and not in others, as well as to inform recommendations about how best to target investments in education to maximize the benefits to health. We will seek to answer the following key research questions, focusing specifically on the mechanisms that affect fertility, HIV, and infant and child mortality. If feasible, these answers will include meta-analyses of comparable education and mediator outcomes: (1) Do changes in education affect the primary theorized mediators (e.g., knowledge, attitudes, resources, and agency; health behaviors and harmful practices) of the relationship between education and fertility, HIV and child mortality? (2) How does the relationship between these mediators and education vary across different aspects of education (e.g., grade attainment vs. literacy/numeracy vs. attendance)?