Among the different methods of changing the color of human hair, oxidative hair dyeing plays an important role. The formulations consist of a broad spectrum of organic compounds among which most of the dye forming substances, i. e. the dye intermediates, are of aromatic nature. With the aim of establishing an analytical method for the separation and quantification of the dye intermediates, the chromatographic behavior of a selection of these products was investigated. The separation was done by HPLC, using reversed-phase chromatography. UV and diode array detection were employed. A quantitative separation procedure was established with which it is possible to separate and identify intermediates according to their retention times and their UV spectra.