The emergence of risk as an organizing concept for regulation and governance has been the subject of considerable comment and debate, most notably in relation to Ulrich Beck's Risk Society thesis. This editorial, however, argues that contemporary preoccupations with risk are driven less by a changing distribution of real, or imagined, ills in society, than by a changing distribution of ills in governance. It argues that the inevitable difficulty of managing threats to society (societal risks) creates threats to organizations managing those risks (institutional risks). The potential for failure has always been part of governance, but contemporary pressures towards greater coherence, transparency and accountability have amplified institutional risks by exposing the practical limits of governance. Framing the objects of governance in terms of risk, however, provides a way of reflexively managing the associated institutional threats by explicitly anticipating the practical limits of governance within probabilistic calculations of success and failure. This editorial outlines how the institutional dynamics of contemporary governance can lead to a phenomenon of 'risk colonization', whereby risk increasingly comes to define the object, methods and rationale of governance. It then goes on to consider some of the possible positive and negative consequences of risk colonization and concludes by suggesting ways in which the study of institutional risk can help us understand the relationship between risk and governance.