Secure attachment relationships play an important protective role against the intergenerational transmission of social exclusion, not only at early stages but at all school levels. LETS CARE aims to comprehensively understand and improve the caring dimension of educational inclusion and school success. The project’s main objective is to identify determinants affecting student security as a root cause of underachievement, disengagement, and school dropout, at 4 different ecological levels: individual, relational, community, and political. LETS CARE will create a theoretical and practical framework to foster Safe Learning, Safe Teaching, Safe Schools and Safe Education at each level as an approach to breaking the chain of transgenerational transmission of educational and social exclusion. This approach will generate lower rates of school failure, poor learning outcomes, and early school leaving. The main proposal breakthrough is based on considering a relational response to educational exclusion and inequality, resulting in a model for understanding the importance of security to address underachievement and early dropout, and a relational approach to inclusive practices at school that will be translated into tools, recommendations, and guidelines for action, from ECEC to secondary and Second Chance schools. Multilevel, multistage, and intersectional research, exploring different European educational contexts, will be implemented, including 120 schools, 18,000 students, and 2,400 teachers from 6 European countries in 4 schools stages, with special attention to multi-disadvantaged learners. LETS CARE, supported by an expert consortium, will implement a holistic methodological approach, including co-creation mechanisms, and will translate research findings into the political approach, through the formulation of novel evidence-based policy recommendations, raising awareness on safe/caring schools, combating social exclusion of disadvantaged learners.