Dye leached from dyed or printed textiles in an aqueous solution can be decolorized by adding enzymes that utilize hydrogen peroxide or molecular oxygen for the oxidation of organic or inorganic substances, including colored substances, together with a source of H.sub.2 O.sub.2 or O.sub.2. Such enzymes are usually termed peroxidases and oxidases, respectively. This treatment reduces the risk of back-straining (redeposition of dye onto textile) even when less water is used. The enzymatic bleaching of released dyestuff will decrease process time as well as the amount of energy and water needed to achieve a satisfactory quality of the textile, and the color of the waste water is reduced.