This work is based on a territorial approach to precariousness and poverty. Using spatial analyzes, the aim is to study how and why socio-economic difficulties appear on various infranational geographic scales, and, ultimately, what are the consequences. First, a typology of territories based on their characteristics related to precariousness and poverty will be developed, using various indicators (in particular concerning low incomes, non-employment and social welfare). Socio-economic factors explaining these profiles will then be investigated. Lastly, the link between demographic renewal and precariousness/poverty will be studied, in order to see the extent to which socio-economic difficulties are accompanied by particular demographic behaviors. Areas where levels of precariousness and poverty are high generally have common features, but the type of territory (urban, periurban, rural) is important too. Whether at the level of metropolitan France's departments or Gironde's districts, areas cumulating difficulties are clearly identified, even if the factors explaining the statistical measures are different. Some territories in particular affected by precariousness and poverty also tend to show specific demographic features: levels of fertility and mortality can notably be high and migratory balance be in deficit.