The family is the primary and most important community in which the child grows and develops, but due to unfavorable circumstances it can also be a risk factor for the child's social exclusion. Some characteristics of parents and characteristics of child care can represent risk factors for the child's well-being and adversely affect the developmental outcome of children, as well as life opportunities in adulthood. ECEC services are recognized as key in preventing the social exclusion risks of early and preschool aged children, and their potential for breaking the vicious circle of social exclusion is emphasized. This paper presents part of the research results of the Croatian Science Foundation “Models of response to the educational needs of children exposed to the risk of social exclusion in ECEC institutions". The aim of this research was to determine how ECEC institutions contribute to the prevention of the risk of social exclusion arising from family characteristics in relation to the reduction of risk factors and the strengthening of protection factors in the child's ecological system. The research covered 65 kindergartens from different parts of the Republic of Croatia. Part of the obtained results refers to the possibilities of parental participation in the educational work of ECEC institutions, and the other part to the possibilities of institutions in providing certain forms of support to families and children at risk of social exclusion. The research found that in most ECEC institutions (57-80%) parents/guardians are offered opportunities to participate in educational work, which includes participation in the processes of defining the goals of educational work, defining strategies and work methods, realizing goals, redefining and evaluating goals. The results indicate the existence of unequal representation of certain forms of support of ECEC institutions to families at risk of social exclusion, where the most represented form of support is individual counseling work (in 95% of kindergartens), and the least represented form of support is group counseling work (in 20% of kindergartens). The results point to the need to standardize and expand the possibilities of cooperation between parents and ECEC institutions with the aim of strengthening the capacity of the ECEC system in preventing the risk of social exclusion of children.