This paper summarizes what is known, and what is uncertain, about strategies what exploit the coercive potential of the criminal justice system to get problem drug users to get treatment for their dependency. It considers the links between problem drug use and crime, the characteristics of effective treatment for problem drug users, the effectiveness of coerced treatment, and the practical obstacles in bridging the gap between criminal justice and treatment services. It draws on experience in Britain, though it is also informed by the English-language research literature, especially that carried out in the United States.