Introduction. Evidence-based practice has broadened and spread into new areas including librarianship. This reorientation has resulted in increased uncertainty regarding what counts as evidence and has caused a tension between formalised procedures and professional judgment. This theoretical paper aims to extend the knowledge about how evidence-based practice can contribute to regulate work and information practices. Method. Data from a small-scale empirical study of social welfare workers was theorised through the lens of institutional ethnography. Analysis. The analysis was primarily guided by the following key concepts: documentary governance, disciplinary mechanism and knowledge mobilisation. Results. Nationally produced statutes, decrees, guidelines, action plans and reports constitute prominent information resources. Knowledge is mobilised when these are read, interpreted, talked about and represented. Evidence-based practice emerges at the same time as a concrete and material activity and as a phenomenon placed in a wider perspective which can be traced through a societal dimension. Conclusions. Evidence-based practice can be viewed as a means to bring about effectiveness but emerges in this study as a disciplinary mechanism through which power is exerted. The theoretical framework has made it possible to elucidate how documents and texts contribute not only to structure but also make things happen in the practice under study.