Abstract: Profiling illicit ecstasy tablets has the potential to become an invaluable tool in the crackdown on drug trafficking, but that potential has yet to be fully realized. The impurity profile of an ecstasy tablet can be used to determine the method employed to synthesize the actual controlled substance, which in most cases, is 3,4-methylenedioxymethamphetamine (MDMA). Tablets can then be linked to a common synthetic route, potentially to a common manufacturer, and possibly even to a common manufacturing batch, based on the impurities present. Current methods for profiling MDMA tablets typically involve extracting the organic impurities for analysis by gas chromatography-mass spectrometry. The potential of profiling the trace metals present in tablets has begun to be investigated while more robust statistical and chemometric procedures are being applied to compare and link tablets. This article reviews the recent advances in MDMA impurity profiling from 2002 up to the end of 2006.