A rich literature in public health focuses on the determinants of health, which can be broadly categorized by their emphases on (1) individual characteristics and behaviors, such as genes, nutrition, exercise, smoking etc.; (2) the physical environment, such as safe water, clean air, housing, and health services; or (3) the social and economic environment, such as socioeconomic status and gender. The emphasis on social determinants has been increasing in the past decade; however, despite the importance of political institutions in shaping the social environment in which individuals live, the functioning of political systems is generally not regarded as a critical determinant of health outcomes. At a minimum, the public health literature posits an indirect linkage via effects on economic growth. In the discipline of political science, the politics of health are receiving increasing attention in current scholarship, yet much of this research focuses on the macro-level, citing how long-run historical processes shape overall health systems and welfare regimes and neglecting political on the individual-level. Based on field research on Lebanon, this paper argues that political competition and, particularly, the nature of Lebanese political sectarianism have a measurably detrimental effect on the health of the population and are key drivers of health disparities. The paper opens with a brief overview of the health status of the population, including health disparities, and then provides a summary description of the health system in Lebanon. The paper then traces the effects of specific formal and informal political institutions on health inequalities, showing through qualitative and quantitative data how partisanship and sectarian loyalties mediate access to basic health care. Based on these findings from Lebanon, the paper then suggests how the arguments apply to additional countries in the Middle East and in other developing regions. The research for this paper is based on over 300 qualitative, in-depth interviews with providers and beneficiaries from the five main sectarian affiliations in Lebanon as well as an original national mass survey (n=2,000) conducted in spring 2008 on political behavior and access to welfare in Lebanon.