This article explores the role that risk plays in different parts of the regulatory process, in order to evaluate the extent to which risk has become an ‘organising principle’ of governance and its implications. This article focuses more specifically on the role that risk plays in constituting, framing, and structuring regulation and regulatory processes, and analyses some of the key themes of the broader risk literature in this context. It argues that risk currently plays four main roles in regulation: providing an object of regulation; justifying regulation; constituting and framing regulatory organisations and regulatory procedures; and framing accountability relationships. This article explores each of these roles. It suggests that in each case, the role of ‘risk’ serves to destabilise decision-making, leading governments and regulators to attempts to find stability through attempts to rationalise processes and procedures, attempts which are often unsuccessful due to the inherent nature of risk itself.