Objectives : The aim of this study was to introduce the concept of health inequalities, and to discuss the underlying assumptions and ethical backgrounds associated with the issue, as well as the theoretical and practical implications of health inequalities. Methods : Based on a review of the literature, we summarize the concepts of health inequalities and inequities and discuss the underlying assumptions and ethical backgrounds associated with these issues from the view of social justice theory. We then discuss the theoretical and practical implications of health inequalities. Results : Health inequality involves ethical considerations, such as judgments on fairness, and it could provide a sensitive barometer to reflect the fairness of social arrangements. Discussion on health inequalities could deepen our understanding of the social etiology of health and provide a basis for the development of comprehensive and integrative social policies. Conclusions : Health equity is not a social goal in and of itself, but should be considered as a part of a broader effort to seek social justice.