The socioeconomic inequalities in health have recently become an important public health concern in South Korea, and the issue has gained increasing attention from many South Korean researchers due to the increasing income inequality and Widening social polarization following its economic crisis in the late 1990s. However, despite the mounting literature on health inequalities published in recent years, the history of research on health inequality in South Korea is premature in comparison to the long histories in several Western countries. Understanding the historical background underlying the issue of health inequality research may aid in establishing and accumulating scientifically solid evidence in South Korea. It may also direct the South Korean research community to develop research agendas that are. more politically and academically appropriate for South Korean society. This paper describes the historical development of health inequality research in the West and introduces several important issues contributing to the advancement of health inequality research. Specifically, the major studies conducted before and after the UK Black Report are presented. In addition, the history and current status of health inequality research in South Korea are documented and evaluated. Finally, several research agendas for the quantitative and qualitative improvement of health inequality research in South Korea are proposed.