Petrochemical manufacturing wastewaters often contain a high concentration of biodegradable compounds that possess either toxicity or activity inhibition to the biological unit. In this paper, a comparison between aluminum and iron plate electrodes on COD and color removal from Petrochemical wastewaters by electro-Fenton process was studied. The experiments were conducted to evaluate the effects of reaction time, current density, pH, H2O2/Fe2+ molar ratio, and H2O2 of petrochemical wastewater (PW) (ml/l) on the performance of the process. Response surface methodology (RSM) was employed to assess individual and interactive effects of the five main independent parameters on the COD and color removal. The results show that COD and color removal efficiencies of iron electrode (67.3% and 71.58%, respectively) were more than those of aluminum electrode (53.94% and 67.35%, respectively).