The aim of this study was to investigate the effect of ethanol exposure on the expression of fos and jun genes. Exposure of human neuroblastoma SH-SY5Y cells to ethanol for 2-4 days caused a dose-dependent increase in c-jun and junD mRNA levels, whereas mRNAs for c-fos, fosB and junB were not detectable in control or ethanol-treated cells. Four days of ethanol exposure also enhanced the AP-1 binding activity. Experiments with actinomycin D demonstrated that ethanol did not influence the degradation of c-jun and junD mRNAs. These results demonstrate that long-term exposure to ethanol increases c-jun and junD expression. This effect may be one of the mechanisms through which ethanol influences the gene regulatory system in neuronal cells.