Abstract: 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 yearly World Drug Report is a contribution towards that objective. This year’s edition starts with an overview of the illicit drug situation worldwide and regionally, followed by more comprehensive discussions and statistical trends for the key transnational drug markets, namely opium/heroin, coca/cocaine, amphetamine-type stimulants and cannabis.