This communication presents the quantitation and differential distribution of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its physiologically active metabolite 3,4-methylenedioxyamphetamine (MDA) in a fatal poisoning following insufflation of MDMA, cocaine and heroin. Animal studies have demonstrated the stereoselective pharmacokinetics and neurotoxicity of these compounds; however, enantiomeric distributions have not been reported in humans. Quantitation of MDMA and MDA enantiomer was by gas chromatography/mass spectrometry (GC/MS) following chiral derivatization with N-trifluoroacetyl-L-triproyl chloride (LTPC). The decedents' blood concentration of S(+)-MDMA was slightly less than that of R(-)-MDMA (1.3 vs. 1.6 mg/l, respectively), while the S(+)- and R(-)-MDA blood concentrations were identical (0.8 mg/l). Both primary routes of excretion, bile and urine, had greater concentrations of R(-)-MDMA than the S(+) isomer. These fluids also contained twice the concentration of S(+)-MDA than the R(-)-isomer. These data indicate that S(+)-MDMA is metabolized and eliminated faster than R(-)-MDMA. The results appear to support the findings in animals regarding stereoselective metabolism of MDMA.