Many illicit drug markets have reached global dimensions and require control strategies on a comparable scale. In that context, there is a need to better understand these transnational markets and the manner in which they operate. The annual Report, produced by the United Nations Office on Drugs and Crime, is a contribution towards that objective. It provides an overview of the illicit drug situation worldwide and regionally, analytical discussions of the key transnational drug markets and statistical trends for all major drug categories.