This Introductory Handbook on the Prevention of Recidivism and the Social Reintegration of Offenders is a revised version of the 2012 publication with the same title. It is part of a series of practical tools developed by the United Nations Office on Drugs and Crime (UNODC) to support countries in preventing crime, implementing criminal justice reforms and strengthening the rule of law. The tools are meant to assist countries in implementing United Nations standards and norms in crime prevention and criminal justice. The publication focuses on the prevention of recidivism and emphasizes the crucial importance of effective programmes to supervise and assist offenders and support their social reintegration. Incarcerated offenders face very real challenges at the time of their release, and communities become unsafe when offenders are released without adequate preparation, supervision or support.