Abstract This project brings together perspectives from different disciplines to gain a deeper understanding of how preventive and early work as well as interventions at a later stage can support children and young people at risk of socially destructive behaviour or who are victims of violence or other forms of maltreatment. The initiative comes from a large municipality which has struggled with severe social problems and marginalisation for many years. Today’s major societal challenges form the point of departure, where the social services in collaboration with other relevant societal actors have a key role in meeting these challenges. The overall aim is to, in collaboration with practitioners and service users, establish a long-term model for knowledge and method development focusing on the social services’ interventions for children and young people. The project has been planned in close collaboration with professionals in the field to gain new and practice-based knowledge about how new interventions and organisational solutions fulfil their aims from the perspectives of children, young people and their families as well as from the professionals’ point of view. The proposed project lies at the centre of the call as it was initiated by and designed in close collaboration with social work practitioners and builds on research questions that are relevant to users’ needs and to the social services’ area of responsibility. The project addresses research areas such as methods for needs assessments and early/preventive measures in the social services. In addition, as service users will be involved in the whole research process, their voices will be heard. As a key point is to implement new knowledge in practice and to create a long-lasting model for knowledge transmission and implementation. Continuing knowledge development in the partner organisation is guaranteed by the involvement of practitioners in the evaluation and development work, and through recurring workshops and method development days for the various units, run in collaboration between researchers and practitioners. Special efforts will be directed to social workers new to the profession to provide special knowledge in the areas addressed in the research projects.The project is forward-looking and focuses on positive experiences and development as well as implementation and organisational learning. The Work Package of most relevance here is focusing on social workers in school and other aktions of crime prevention among school children.