Over the last 15 years, numerous deaths involving "Ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) have been reported and described in the literature. In most cases, either antemortem or postmortem concentration data are available. Because of the wide range of results and potential idiosyncratic nature of MDMA toxicity, interpretation of both antemortem and postmortem concentrations is difficult. The possible influence of postmortem redistribution may be an overlooked factor, but existing data involve postmortem concentrations from varying anatomical sites. However, this paper describes for the first time an evaluation of the concentrations of MDMA and 3,4-methylenedioxyamphetamine (MDA) found in five fatalities admitted to hospital where both antemortem and postmortem blood samples were available. Admission MDMA and MDA concentrations ranged between 0.55 and 4.33 mg/L and 0 and 0.10 mg/L, respectively, in antemortem serum/plasma. Postmortem blood MDMA and MDA concentrations ranged between 0.47 and 28.39 mg/L and 0.02 and 1.33 mg/L, respectively. Postmortem concentrations were higher than corresponding antemortem concentrations in all 5 cases with postmortem/antemortem ratios between 1.1 and 6.6 for MDMA and 1.5 and 13.3 for MDA. Differences in concentrations were also observed between anatomical sites, with central sites (e.g., heart) having much higher concentrations than peripheral sites (e.g., femoral). Overall, MDMA and MDA appear to exhibit postmortem redistribution and concentrations measured in postmortem specimens (even from peripheral sites) are not directly comparable with antemortem findings close to or prior to death.