Approximately equieffective doses of d- and l-amphetamine, using suppression of operant fixed-ratio responding for food reinforcement as the determinant of potency, were compared for their ability to alter the disposition of the major and minor metabolites of NE in push-pull perfusates from rat brain lateral ventricle. While 3 mg d-amphetamine/kg and 6 mg l-amphetamine/kg both increased total 3H and the relative amounts of the minor metabolites 3H-normetanephrine and 3H-dihydroxymandelic acid, only 1-amphetamine caused a significant increase in the major 3H-NE metabolite, methoxyhydroxyphenylethylene-glycol. The data is discussed in relation to the abilities of the isomers of amphetamine to stereoselectively interact with noradrenergic neurons at doses that produce similar effects upon operant behavior.