This report presents the results and outlines the key achievements for 2011 on the information exchange, risk-assessment and control of new psychoactive substances. New drugs were detected in the European Union in 2011 at the rate of around one per week, with a total of 49 new psychoactive substances officially notified for the first time via the EU early-warning system (EWS). This represents the largest number of substances ever reported in a single year, up from 41 substances reported in 2010 and 24 in 2009. In 2011, the list of substances registered was dominated by two groups: synthetic cannabinoids (23 substances) and synthetic cathinones (8 substances). These now represent the two largest drug groups monitored by the EWS and, together, make up around two-thirds of the new drugs reported last year. All of the new compounds reported in 2011 were synthetic. Also described in the report is the EMCDDA's monitoring of the online ‘legal high’ market. The number of online shops offering at least one psychoactive substance or product rose from 314 in January 2011 to 690 in January 2012.