A process for the fractionation of valuable fractions from cereal brans (e.g. wheat, barley and oat brans, and rice polish) is described. In particular, this invention describes a two step process, in which the said bran is first subjected to a combination of enzymatic treatment and wet milling, followed by sequential centrifugation and ultrafiltration, which aims at physically separating the main bran factions, i.e. insoluble phase (pericarp and aleurone layer), germ-rich fraction, residual endosperm fraction and soluble sugars. A second step consists of fractionating cereal brans substantially free of soluble compounds, hence insoluble phase from the above-mentioned first step, by enzymatic treatment with xylanases and/or beta-glucanase and wet milling, followed by sequential centrifugation and ultrafiltration, which aims at physically separating the main fractions, i.e. insoluble phase (remaining cell wall components), protein-rich fraction, soluble hemicellulose and oligosaccharide, and therefore maximizes the extraction rate of valuable cell wall components and aleurone cells from previously cleaned bran.