We used B 16 melanoma cells both in vitro and in vivo to determine whether Flavone acetic acid (FAA) can increase the cytotoxicity of mitomycin C (MMC) under normothermic and hyperthermic (HT) conditions. The significantly increased cytotoxicity of MMC combined with FAA and HT seems to be mainly related to activation of alkylating species under FAA mediated hypoxic condition.