Within the past decades, multiple novel opsins have been identified and localized to extraocular sites in nonmammalian vertebrates. However, adult mammals have traditionally been thought to lack of extraretinal photoreceptors, given the fact that intact eyes are needed to entrain many physiological processes. Encephalopsin and melanopsin were the first putative extraocular opsins identified in mice but not in human brain. We have studied the distribution and localization of opsin proteins in human and mice brain of ten male individuals, using Western blotting and immunohistochemistry. Selected peripheral tissues were also analysed. The specificity of immunoreaction was validated by primary antibody omitting and immunizing peptide blocking experiment. We found encephalopsin protein abundant both in human and mouse brain, but not in periphery. Encephalopsin protein was present in neurons of mice cerebral cortex, paraventricular area, and cerebellar cells. Contrary to what had been expected, melanopsin protein was found in all 18 sites of human brain supporting previous reports showing extravisual opsin genes expression in mammalian brain at mRNA-level. Therefore, the suggested idea that opsins play a role in non-visual photic processes seems to be applicable. Evidently, further investigations are needed to find out the signalling mechanisms, and the potential physiological role of mammalian opsins in phototransduction due to the changes in ambient light.