Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers. In this article, we investigated the enzymatic treatment of three estrogens (estrone, 17beta-estradiol, and 17alpha-ethynyletstradiol) by a fungal laccase which oxidize phenolic compounds with dissolved oxygen. The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay. In addition, we developed an enzymatic treatment system comprised of beta-D-glucuronidase and the laccase for 17beta-estradiol 3-(beta-D-glucuronide) degradation. The two enzymes eliminated 17beta-estradiol 3-(beta-D-glucuronide) and the intermediate, 17beta-estradiol, efficiently.