Social work in Sweden is part of a municipal public system which also takes into account migrant children. As the policing of in Sweden and Europe is increasing, this system is now being governed on various institutional levels in order to find a difficult equilibrium between child welfare and migration control. Using policy documents from a national project, this essay analyses an example of such government. In this project co-operation between municipal public social work, the Swedish Migration Agency, the Swedish Police and local NGOs is encouraged in order to target children with an insecure asylum status in Sweden. The main aim is to investigate how migrant children, especially those with an insecure asylum status, are represented in this project, and how this, in turn, legitimizes co-operative solutions for Swedish social work that further detention and deportation in the name of child welfare. In this context, representations of migrant child mobility and perceptions of ‘un-childish’ childhood connected to the policing of migrant mobility in Sweden and the Europe are taken into particular consideration.