OBJECTIVE: to characterize the profiles of families in the area covered by a Primary Health Center and to identify those in a vulnerable situation. METHOD: this is an epidemiological, observational, cross-sectional and quantitative study. 320 home visits were made, defined by a random sample of the areas covered by the Urban Center 1 in the city of São Sebastião, in Brazil's Federal District. A structured questionnaire was used for data collection, elaborated based on the Family Development Index (FDI). RESULTS: there was a predominance of young families, women, and low levels of schooling. The FDI permitted the identification of families in situations of "high" and "very high" vulnerability. The most critical dimensions were: "access to knowledge" and "access to work". CONCLUSION: the study indicated the importance of greater investments in the areas of education, work and income, and highlighted the need for the use of a wider concept of vulnerability by the health services.
Family; Health Evaluation; Vulnerability; Primary Health Care; Needs Assessment; Comprehensive Health Care