All around the world, not only persistence, but also growing health inequalities. Quebec is no exception: it has been estimated that around five years of life expectancy and almost 15 years of healthy life are separating the most disadvantaged from the most advantaged groups. This difference is only partly explained by the unequal distribution of material resources. The causes are clearly more complex and should be defined as rigorously as possible. Supported by the Quebec People’s Health Research Network, this book brings together the contributions of authors to a wide range of expertise. Social epidemiology and sociology, but also psychology, geography, anthropology, neurobiology and programme evaluation are thus one of the avenues used to address an evolving subject matter. Solutions to this important public health and equity problem will require knowledge sharing and complementarity of opportunities.