Abstract The aim of this qualitative case study was to examine social service workers and managers approach towards the implementation of the Signs-of-Safety (SoS) model and their comprehension of working with the model. This study took place at a children and youth unit at a social service office in Stockholm. The empiric is based on three qualitative semistructured interviews and participant observations. The result was analyzed by definitions from Hasenfeld’s Human service organizations (HSO), Lipsky’s and Johansson’s definitions of "street-level bureaucrats", and room for manoeuvre. Lundquist’s definitions of "understand", "want" and "can" was also used, as well as the core-components that Fixsen, Naoom, Blase, Friedman och Wallace draw together of a successful implementation. The main result of the study indicates that the SoS-model contributes to the participation of children and parents and that it is complicated to implement the SoS-model in such a specialized organization. The study’s result also shows that the implementation is promoted by the support and the resources of every level in the organization and the fact that the initiative came from the street-level bureaucrats. The documentary system that comes with the BBIC is complicated to combinate with the SoS-model and therefore this might become a restricting effect.