The study is focused on those households in which the mother alone takes care of her dependent children, known in Spain as “monomarentales”. This is a new concept, which has been introduced in order to give visibility to the feminine nature of single parenthood and denounce their situation of vulnerability. In fact, these family groups are exposed to a higher risk of poverty and social exclusion. For this reason, they go to Social Services more frequently. On the basis of these premises, an exploratory study was carried out with a double objective: on the one hand, to find out the professional assessment that social workers of front-line Social Services make about the situation of needs experienced by the single-mather and, on the other hand, to identify new ways of social intervention, from the point of view of the professionals who work with these families. In order to achieve both objectives, a synchronic and local study has been chosen, based on a qualitative methodological desing that is organized in two phases. In the first one, a semi-structured in-depth interview has been conducted with a group of social workers who regularly attend to mothers in front-line Social Services. In the second, a discussion group has been carried out, integrated by these same professionals. The results allow us to systematize their experience with single-mother families and to specify new strategies of social intervention that are innovative.