The first EMCDDA Trendspotter meeting, on Recent shocks in the European heroin market: explanations and ramifications, took place in Lisbon on 18–19 October 2011. The purpose of the meeting was to increase understanding of the 2010/2011 heroin shortage reported by some European countries and to explore issues of drug replacement. Sixteen experts from 14 European countries presented their experiences of recent trends in heroin availability and use and the replacement of heroin by other illicit drugs or medicines, providing insights from different disciplinary perspectives.