The microbial degradation of bisphenol A (BPA), 4- n -octylphenol (OP) and 4- n -nonylphenol (NP), endocrine-disrupting chemicals (EDCs), by 7 strains of industrial koji molds ( Aspergillus oryzae ) was studied. More than 50% of the biodegradation of BPA was apparent in a 6-days agar plate culture by using 5 strains of A. oryzae . The degradation of OP and NP proceeded relatively more easily than BPA. Most strains degraded more than 50% of OP and NP even with only 3 days of culture. The similar degradation of EDCs occurred in a surface-liquid culture. OP and NP were also degraded with A. oryzae KBN606 in koji-making used whole soybeans. These findings suggest the possibility that BPA, OP and NP may be degraded during the koji-making process in the production of traditional fermented foods, even if the ingredients and/or water were contaminated with these EDCs.   In this study, we also found that OP and NP were easily degraded by the mycelia of A. oryzae KBN606. This fact suggests that the mycelia can be used to remove OP and NP contaminants as a bioremediation tool.