What role does the government ideological composition play in health policy formation? According to the conventional view, left-oriented governments are more likely to increase health spending, however, the impact of ideology on health policy outcomes is still a question of discussion. This paper examines how the ideological differences of the ruling parties influence the efficiency of health systems. Authors use the 4 stage data envelopment analysis (DEA), a non-parametric approach, to measure the health efficiency of 31 OECD countries for the period of 2001-2016. Based on results from the panel Tobit Regression model, authors show that while left-winged governments increase the public health spending, the efficiency of health systems is higher under ideologically balanced and/or right-winged governments.