This joint report prepared by the EMCDDA and Europol considers the latest findings from international research, fresh empirical data, and operational information and intelligence in order to illuminate how darknet markets function and how they relate to criminal behaviour. The publication adopts an EU focus of what is a global phenomenon. It is comprehensive but accessible and policy-oriented, intended to facilitate discussions at EU-level on how to respond to darknet drug markets, whilst identifying key priority areas that require attention and where activities are likely to have most impact.