Carbamazepine and diclofenac were frequently detected in water bodies. In this study, crude lignin peroxidase, produced from a white rot fungus Phanerochaete chrysosporium, was studied on its in vitro degradation of both drugs. The influencing parameters were studied, including pH, the hydrogen peroxide concentration, veratryl alcohol and the temperature. It was found that UP completely degraded diclofenac at pH 3.0-4.5 and 3-24 ppm H2O2 while the degradation efficiency of carbamazepine was mostly below 10%. The addition of veratryl alcohol and the increased temperature did not enhance the degradation of carbamazepine. (C) 2009 Elsevier B.V. All rights reserved.