In the context of HIV infection, the disappearance or inability to assume their parental role of one or both parents has focused attention on the generation of grandparents who are responsible for the offspring. It is only when they are unable or no longer able to do so that uncles or aunts, or even to a lesser extent friends, take on this role. The Social Services Departments step in as a last resort when there is no kinship option. However, the environmental vulnerability of these families and their psychosocial risk factors, which preceded the advent of HIV, are often the reason of the placement of children . Analysis of the interviews carried out on 36 family members and 20 professional foster families records their involvement on a day-to-day basis with the children, for the most part HIV- infected. It also highlights the constraints and difficulties involved in what is an extreme form of family solidarity, compared with the structured support of institutional care, which in turn has its own limitations.