A method is described for the determination of cocaine, benzoylecgonine and cocaethylene in the human brain using Clean Screen solid phase extraction cartridges and gas chromatography/ion trap mass spectrometry with electron impact and full scan analysis. The procedure uses deuterated internal standards. Run-to-run and within-run coefficients of variation are < 7% and the sensitivity proved to be 50 ng/g from 1 g of sample. The procedure has been applied to a number of forensic cases involving cocaine intoxication. Cocaine was relatively unstable in brain tissue stored at 4 degrees C when compared to storage at -80 degrees C.