In this article, we focus on how social workers use their agency when implementing top-down policy measures as street-level bureaucrats. We report on findings of a case study that was conducted in Flanders, the Dutch-speaking region of Belgium, about the top-down introduction of an electronic information system (IS) in the field of Child Welfare and Protection (CWP). Starting from insights derived from neoinstitutional theory, we explore how social workers perform a role as so-called 'institutional entrepreneurs' by initiating critical reflections about policy rationales. In our contribution, we show that, despite social workers' awareness of being embedded in their own field or service area, they use their field-level expertise and day-to-...