Introduction. Early childhood educational and care services have recently adopted the goals of social inclusion and ending child poverty. These objec-tives are aligned with the aims of primary care social services implemented by social workers. The access rates of impoverished families to these schools, however, are particularly low. Adopting an institutionalist approach, we analysed the regula-tory and organisational conditions that frame how social workers in primary care social services pro -mote the access of children aged 0-3 years to public schools. Methodology. This analysis of primary care social services in the city of Tarragona was based on semi-structured interviews with social workers (17) and discussion groups (8). Results. Given the lack of vacant school places and the scarcity of resources in primary care social services, social workers' nar-ratives showed that access to these schools was not conceived as a family's 'right >> (universalist institu-tional logic). In contrast to the academic consensus, social workers in primary care social services are not aware of, or do not consider the emotional, cogni-tive, and relational benefits of entering the education system at an early age. The prevalent view is that young children are to be cared for by their parents (and the extended family). In fact, taking full-time care of children is often thought of as enhancing adults' responsible nature in other domains than parenting. This familistic logic prevails in this institutional framework and professionals should mobilise several rationalities to prioritise the (few) users who obtain help from primary care social ser-vices to access these schools. Firstly, these schools are used by primary care social services to partially replace the family when children are considered 'at risk >> (e.g., lack of adequate nutrition or suspected negligent parenting practices). In this case, the practices of primary care social services regarding these schools reproduce the residual and subsidi-ary traits that have historically shaped anti-poverty policies in Southern Europe. Second, access to these schools can be favoured when schools are framed as a necessary 'resource >> that frees parents from care tasks, allowing them to undertake actions of the social intervention plan (e.g., basic skills training, language courses, participation in relational activ-ities) (professional institutional logic). Third, these schools can be considered as a key means of support when a job opportunity arises and no informal sup-port is available to care for the children (institutional logic of activation). Discussion and conclusions. An institutionalist analysis allowed the identification of some of the elements that influence social welfare organisations within social contexts of inequality. In this sense, this study exposed some aspects of professional practices in primary care social services which cannot be explained by manifest goals or methodological prescriptions. Such knowledge can facilitate the design and implementation of more effective social service policies.