Regulation and governance of medical research is frequently criticised by researchers. In this paper, we draw on Everett Hughes' concepts of professional licence and professional mandate, and on contemporary sociological theory on risk regulation, to explain the emergence of research governance and the kinds of criticism it receives. We offer explanations for researcher criticism of the rules and practices of research governance, suggesting that these are perceived as interference in their mandate. We argue that, in spite of their complaints, researchers benefit from the institutions of governance and regulation, in particular by the ways in which regulation secures the social licence for research. While it is difficult to answer questions such as: "Is medical research over-regulated?" and "Does the regulation of medical research successfully protect patients or promote ethical conduct?", a close analysis of the social functions of research governance and its relationship to risk, trust, and confidence permits us to pose these questions in a more illuminating way.