A method was developed and fully validated for simultaneous quantification of methamphetamine (MAMP), amphetamine, hydroxy-methamphetamine, methylenedioxymethamphetamine (MDMA, ecstasy), methylenedioxyamphetamine, 3-hydroxy-4-methoxy-methamphetamine, and 3-hydroxy-4-methoxy-amphetamine in 100 microL mouse plasma and 7.5mg brain. Solid phase extraction and gas chromatography-electron impact ionization mass spectrometry in selected-ion monitoring mode achieved plasma linear ranges of 10-20 to 20,000 ng/mL and 0.1-0.2 to 200 ng/mg in brain. Recoveries were greater than 91%, bias 92.3-110.4%, and imprecision less than 5.3% coefficient of variation. This method was used for measuring MAMP and MDMA and metabolites in plasma and brain during mouse neurotoxicity studies.