This report presents the results and outlines the key achievements for 2010 on the information exchange, risk-assessment and control of new psychoactive substances. In 2010, 41 new psychoactive substances were officially notified for the first time in the European Union through the Early-Warning System (EWS). Of those, 15 were synthetic cathinones and 11 were synthetic cannabinoids. Substances belonging to more established chemical families were also reported – five phenethylamines, one tryptamine and one piperazine. The list of newly notified substances was rather diverse and also included a plant-based substance, a synthetic cocaine, a ketamine derivative, a phencyclidine derivative, an indane, a benzofuran, as well as a substance which can be seen as a designer medicine. The report also describes the increased availability of 'legal highs' and the EMCDDA's activities in monitoring the online shops selling these products, as well as the risk assessment of mephedrone, which was submitted to control measures and criminal penalties throughout the European Union.