Marine pollution problems have been noted in increasing manner depending on the increment in sea transportation every succeeding day. Bilge water can be count as one of the main pollution source, which contains petroleum, oil and hydrocarbons in high concentrations. Due to interference of seawater to the bilge water, it contains in high chloride concentration; and therefore it is high in conductivity. This feature is an advantage for treatability of bilge water by electrochemical processes. High conductivity leads to increment of current intensity and decrement in voltage and energy costs. Contrary to conventional chemical treatment, extra consumption of chemicals can be avoided by electrochemical treatment methods. In this study, treatment of bilge water by electrocoagulation/electroflotation process is investigated. The experiments were carried out in accordance with statistical runs assigned by response surface methodology. Before optimization via response surface methodology, a pre- study was performed and the highest removal efficiencies in all pre- studies are obtained in original pH (pH6,95). in consideration of pre- studies, statistical runs were carried out and, the optimum removals of both COD and Oil & Grease were obtained under 9,87 mA/cm(2) of current density in approximately 13 minutes and in approximately 29 degrees C of inlet temperature; optimum COD and Oil & Grease were removed by 90,3% and 81,7%, respectively.