This report reviews the global situation regarding Cannabis cultivation and use, with particular reference to recent debates around the variable THC content of Cannabis products, and the link between use of the drug and mental health problems such as schizophrenia and psychosis. Having analysed the prevalence and potential for health and social problems arising from Cannabis use, the authors then move on to consider the various policy and programme options available to governments in their attempts to minimise the harm arising from the use of this particular drug.