The report outlines the results of the implementation of the Council Decision in 2005 and describes some issues arising from the initial experiences. In 2005, 14 new psychoactive substances were officially notified for the first time through the information exchange mechanism/EWS set up by the Decision. All newly-notified substances belonged to three major chemical groups – phenethylamines, tryptamines and piperazines. Of these 14 substances, three were of particular note, methylone, DPIA and mCPP, as exhibiting characteristics that suggested that they were particularly appropriate for targeted monitoring and further vigilance. The report raises important issues and implication for the implementation of the Council Decision, in relation to the case of mCPP, which was not recommended for formal risk assessment.