Background: Among various pollutants, fine particle (PM2.5, defined as particle less than 2.5 nm in aerodynamic diameter) shows the most consistent association with adverse health effects. There is scientific evidence documenting a variety of adverse health outcomes due to exposure to PM2.5. Objectives: This study aims to assess the health benefits of that would be achieved by meeting the World Health Organization’s air quality guidelines for PM2.5 using AirQ+ and BenMAP. Methods: We estimated PM2.5 related health benefits in Korea from implementing the World Health Organization’s air quality guidelines (annual average 5 μg/m3 and 10 μg/m3) and Korea’s National Ambient Air Quality Standard (annual average 15 μg/m3). We used World Health Organization’s AirQ+ and U.S. Environmental Protection Agency’s Environmental Benefits Mapping and Analysis Program. Results: The annual number of avoided PM2.5 related premature deaths exceeding WHO guideline levels was assessed using both AirQ+ and BenMAP. We estimated that the health benefits of attaining the World Health Organization’s air quality guidelines for PM2.5 (annual average 5 μg/m3) would suggest an annual reduction of 26,128 (95% confidence interval [CI]: 17,363~34,024) and 26,853 (95% CI: 18,527~34,944) premature deaths. Conclusions: Our study provided useful information to policy makers and confirms that the reduction of PM2.5 concentration would result in significant health benefits in Korea.