A UV-Vis and Raman spectroscopy study of three aminochromes generated through Mn 3+ oxidation of the dopamine, l-dopa and adrenaline molecules at physiological pH was performed. The UV-Vis spectra of the catecholamines oxidized using Mn 3+ in buffer solution at pH 7.2 show a band at ca. 300 nm, formed by two transitions at 280 nm and 300 nm assigned to an L a and L b transition respectively, and other at ca. 470 nm assigned to an n–π* transition localized in the carbonyl group. This assignment is suggested by the UV-Vis and Raman spectra of ortho-aminoquinone generated by MnO 2 oxidation of a dopamine aqueous acidic solution. The resonance Raman spectra of the three chromes at buffer pH 7.2 show a very similar feature and the most intense bands are observed in the spectral range 1100–1800 cm −1 . The band around 1680 cm −1 for the three compounds is assigned to a ν(CO) stretching vibration, 1630 cm −1 to the ν(CC) ring mode, two bands at 1423, 1439 cm −1 ; 1427, 1438 cm −1 and 1456, 1475 cm −1 are assigned to a ν(CN + ) vibration, for aminochrome, dopachrome and adrenochrome, respectively. The excitation profiles for the most intense bands for aminochrome and adrenochrome were obtained. The band assigned to the ν(CN + ) present a red shift with respect to the visible band peak, however the band in adrenochrome at 1475 cm −1 shows a profile similar to ν(CO) and ν(CC) modes that reflects the methyl group effect on mixing this mode more effectively with the ν(CC) ring mode.