Gambling is a legitimate leisure activity in many countries that many people use. However, some of them suffer significant harm because of gambling. This may involve economic, social, physical or mental harm. These harms are not only suffered by the individual gambler, but affect the family, the community and society. The aim of this text is to propose a conceptual framework for understanding the determinants of gambling and its related harms and thus, contribute to the development of prevention policies to reduce its impact on health. The framework proposed in this manuscript places present evidence in the model of health inequalities, analyzing the effect of the socioeconomic and political context, the axes of inequalities, individual and social factors, and the health system in generating the health inequalities of gambling suffered by the most vulnerable groups. The evidence gathered in this framework suggests that health determinants lead to health inequality in relation to gambling and its associated harms.