Risk thinking is transforming the understanding, organisation and management of health care systems, and its significance is likely to increase still further over the next two decades as technological advances, for example the new genetics and the discovery of new biomedical markers, open up novel possibilities for health risk management. Heightened societal risk consciousness, such as food panics and the debate over the MMR vaccine, co-exists, apparently paradoxically, with increased life expectancy in advanced industrial societies and increasing concern about the longer term future. At the same time, social trends are pushing health care systems towards the surveillance of populations and the targeting of groups identified as being at higher risk. All too often, service users, health professionals, policy makers and researchers draw upon a risk management framework without reflecting critically on its assumptions or limitations. This introductory text focuses on the underlying generic issues of risk management in a health care. Aimed at health professionals, managers, educators and policy makers who are concerned with risk management, it allows the reader to analyse risk management issues, and to critically evaluate the claims made about existing and new technologies, in an informed way. It covers all aspects of risk relevant to a clinical setting and is closely related to decision making in the clinic.