Social inequalities in health include all the impacts caused by the different social characteristics of individuals on their health. They strongly influence the health status of the French population. Socio-professional category, gender and ethnic origin are all determining factors in the health of people who, however, are not dependent on the healthcare system. Action in the healthcare field will therefore focus on the effects of these inequalities, to limit the number of people who forego healthcare, and to promote collective and individual health.