Despite extensive empirical research, there is little agreement on how and why political regimes affect social and economic development. This paper expands on this literature by examining how political regimes affect health policies relating to the treatment of HIV/AIDS. The paper examines whether multiparty competition matters for access to treatment of HIV/AIDS and then moves on to analyse the effect of electoral systems. Using regression and matching methods on data for a broad cross-section of countries, the results show that democracy on average increases access to treatment of HIV/AIDS. However, only democracies using proportional electoral systems that allow for greater representation of minority interests rather than plurality voting differ significantly from autocracies.