The immunocytochemical distribution of retinoid receptors has been analysed in the mouse adult central nervous system. All retinoic acid receptors (α, β and γ) and retinoid X receptors (α, β and γ) were detected and found to exhibit specific patterns of expression in various areas of the telencephalon, diencephalon and rhombencephalon. The protein localization of several retinoic acid receptors and retinoid X receptors did not correlate with the distribution of the corresponding RNA transcripts, as studied by in situ hybridization and RNase protection assays. This suggests that the expression of retinoid receptors could be post-transcriptionally regulated, which may contribute to their specific localization in the adult nervous system.