The effect of ethanol (etOH) on dopamine (DA) metabolism in the caudate nucleus (CN), olfactory tubercle (OT) and medial prefrontal cortex (MPFC) was compared in 2 selectively bred lines of rats, one etOH-preferring (sP) and the other -non preferring (sNP). EtOH (2 g/kg per os), administered 60 min before killing, caused a significant increase in concentrations of the DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and reduced DA levels in CN and OT in sNP rats. On the other hand in sP rats, etOH increased the content of DA metabolites in all the 3 areas analyzed. These changes induced by etOH in DA metabolism were significantly greater in sP than in sNP rats. The above data indicate that sP rats have a genetic high sensitivity to etOH effect on DA metabolism probably linked to etOH preference.