This report published by the Beckley Foundation Drug Policy Programme in partnership with the International Centre for Prison Studies at Kings College London, revisits the topic of the incarceration of drug offenders. The report provides an overview of some of the available incarceration data from around the world and brings together much contemporary research on the topic. A great deal of the discussion concerns one of the most enthusiastic supporters of incarceration as a drug prevention measure, the United States.  It is suggested however, that the results of policy within the United States should be used as evidence to encourage other member states not to follow this route.