The present study was carried out to asses possible toxic effects of 3,4-methylenedioxyethylamphetamine (MDE) on serotonergic, dopaminergic or noradrenergic neurons in the rat brain. It was found that MDE produced a long-lasting, dose-related depletion of serotonin (5HT). However, even at high dosage, MDE did not reduce the concentration of either dopamine (DA) or norepinephrine (NE) on a long-term basis. When compared to 3,4-methylenedioxymethylamphetamine (MDMA), MDE was approximately one fourth as potent as producing a long-term depletion of 5HT. These results suggest that MDE, like MDMA, may be selectively toxic to central serotonergic neurons.