Wool/nylon fabrics were treated with enzymes and hydroperoxide for the purpose of bleaching. The effects of enzyme treatment under various conditions on the whiteness and strength of the fabrics were studied. The whiteness of fabrics treated with protease was the best and comparable to that obtained with hydroperoxide treatment. The strength of fabric treated with Alcalase decreased slightly in the beginning, then began to decrease rapidly. The optimum time for acceptable whiteness and strength of the fabric treated with Alcalase was 40 minutes. The treatment with compound enzymes was not effective, and the treatment with hydroperoxide following Alcalase treatment enhanced whiteness and showed the middle value of strength retention between the other two treatments. Protease bleaching is useful especially in the case of wool/nylon blends because nylon was attacked by hydroperoxide at long treatment times.