Increasingly, social workers and social-welfare agencies are concerned in their day-today policies and practices with the issue of risk. Risk assessment, risk management, the monitoring of risk and risk-taking itself have become common activities for both practitioners and managers. Similarly, estimations about risks have become key in identifying priorities and making judgements about the quality of performance and what should be the central focus of professional activities. The purpose of this chapter is to identify some of the areas of social work where notions of risk have taken on a particular significance and to begin the process of analysing what is meant by the term. More fundamentally, however, I want to address why it is the issue has become so important in recent years. My central argument is essentially that risk is not a thing or a set of realities waiting to be unearthed but a way of thinking. As a consequence, social work’s increasing obsession(s) with risk(s) point to important changes in both the way social workers think about and constitute their practices and the way social work is itself thought about and thereby constituted more widely.