Harm reduction encompasses interventions, programs, and policies that seek to reduce the health, social, and economic harms of drug use to individuals, communities, and societies. Harm reduction is envisioned as a 'combination intervention', made up of a package of interventions tailored to the local setting and need, which give primary emphasis to reducing the harms of drug use. Harm reduction is now positioned as part of the mainstream policy response to drug use in Europe. This monograph comprehensive in scope provides a state-of-the art a review of the role of harm reduction strategies and interventions provided by the European Monitoring Center for Drugs and Drug Addiction (EMCDDA). A number of contributors explore what harm reduction means and what policies it can encompass, as well as charting how the concept evolved. They reflect on both harm reduction practice and the evidence base for its effectiveness. Contributors touch on the difficulty of assessing how complex interventions occurring in real world settings can be evaluated. Contributors wrestle with the difficult issue of how harm reduction might be extended into new areas that are of particular relevance to the evolving European drug situation. Harm reduction, overall, as a concept is now accepted as part of a balanced approach, an integral element of a comprehensive strategy that includes prevention, treatment, social rehabilitation and supply reduction measures. Tables, figures, and references