It is possible to discern a new trend replacing New Public Management (NPM) in human service organisations. This trend comprises a discussion about evidence and governance with the goal of establishing a knowledge-based practice within Swedish social service. Efforts aimed at promoting an evidence-based practice have been an explicit part of Swedish social policy for more than 15 years. As a public venture aimed at changing local municipality social work practice, the initiative described in this article has few predecessors in terms of personnel, finance, or political support. The purpose of this article is twofold: first, to describe the intervention and its implementation, and second, to analyse the intervention and its implementation and some implications of them. The article uses translation and institutional theory. The overall aim is to analyse the intervention and its implementation from the perspectives of power and governance. The empirical data include documents, interviews, and a survey of professionals. Data were collected between 2009 and 2016. This article shows that the intervention has been interpreted and reinterpreted during its implementation, and that the intervention has not yet created any radical change or knowledge development in social work practice. The article argues that evidence-based governance and other forms of governance constitute a successor of NPM, though far from a complete replacement. It is also obvious that actors such as researchers, professionals, and clients seem to have limited influence over future knowledge development within social services.