In recent years, there have been critical improvements and changes in health systems and health care. These issues have caused a dramatic increase in the cost of health care and health expenditure all around the world. It is, however, not sustainable. Therefore, governments have been seeking ways to reduce the costs of services in the health sector. In this context, it was aimed to figure out the predictors of health expenditure in OECD and a panel data analysis covering the period of 2000-2017 was used to achieve the main objective of the study. It was found that income (beta: 1.331) and education (beta: 0.062) were the most important factors affecting health expenditure in OECD (p < 0.05) and also, that unemployment rate and dependency ratio had not statically significant effect on health expenditure (p > 0.05). Additionally, it was seen that health expenditure in OECD had increased for years. In this context, it can be concluded that health expenditure will continue to rise. Thus, it is suggested that the following studies should focus on the efficiency and the effectiveness of health expenditure for the sustainability.