The effects of 5 weeks' ethanol treatment on the number and affinity of cortical and striatal dopamine D1 receptors and striatal D2 receptors in rat brain were investigated. The ethanol and control diets were carried out using the pair-feeding technique. The number and affinity of dopamine D1 receptor sites in the frontal cortex and caudate-putamen or D2 receptors in the caudate-putamen were not significantly altered by the used ethanol dose regimen. This study demonstrates that if dietary factors related to ethanol consumption are carefully controlled no 'specific' ethanol-induced changes in striatal D1 and D2 or cortical D1 receptor characteristics can be observed after 5 weeks' ethanol consumption. Thus, changes in the central dopamine receptors are not likely to play any significant role in the effects of moderate ethanol consumption on neuronal function.