The feasibility of cotton-bleaching with enzymatically produced hydrogen peroxide (H₂O₂) was investigated in this study. Glucose oxidase (GOD), catalyzing the generation of H₂O₂ from glucose oxidation, was used as a model enzyme. When 0.1 M glucose solutions were treated in order to achieve the production of H₂O₂ to 0.1% (w/w) enough for cotton-bleaching, the reaction was found to be limited by oxygen supply rates. Also, the remaining glucose caused the development of yellow color in cotton bleaching. When the initial concentration of glucose was reduced to 0.05 M, and the oxygen was supplied at 1.0 L O₂/min, the levels of H₂O₂ were maintained at about 0.07% (w/w), and the concentration of the remaining glucose was negligibly low. In bleaching desized cotton fabrics, the whiteness level obtained with enzymatically produced H₂O₂ (0.07% (w/w)) was comparable to that with commercially available H₂O₂ (0.1% (w/w)).