Multiagency collaboration between state and municipal actors such as schools, social services and the police is at the core of the Nordic countries’ approach to preventing radicalization and violent extremism. Yet, assessment of reported concerns of radicalization differs across countries. This qualitative study analyze how professionals negotiate assessments to identify factors that shape whether a concern of radicalization develops into a perception of risk. We argue that differences in structural factors and “institutional logics” in addition to trustful relations between practitioners at the local level affect collaboration and shape the perception of the task when the assessments of concrete concerns are negotiated.