The removal of bisphenol A from aqueous solutions was examined using a culture broth of Coprinus cinereus as a source of peroxidase. Bisphenol A was efficiently removed by a polymerization and precipitation method catalyzed by peroxidase. The removal efficiency was optimal between pH 9–10 and at 40°C, and at a molar ratio of H₂O₂ to bisphenol A of about 2.0. To remove 100 mg/L bisphenol A, 3 U/mL peroxidase was required at pH 10 and 40°C, and 5 U/mL at pH 7 and 25°C. The acute toxicity of the bisphenol A solution, which was estimated using a bioluminescence method, decreased with the peroxidase treatment and became almost zero when the removal efficiency became 100%. Also, the estrogenic activity decreased due to the treatment.