The electrooxidation as a new treatment technology for the purification of petroleum refinery wastewater was used. About 85% COD reduction and complete removal of total petroleum hydrocarbon was achieved for the optimal conditions of current density 30 mA/cm2, pH 8, supporting electrolyte 4 g/L, flow rate 120 LPH, and treatment time 24 min using tubular electrochemical reactor. The result shows the applicability of electrochemical technology as an alternative for recycle and reuse of petroleum refinery wastewater. This technology decreases the time required for treating the petroleum effluent, the volume of consumed water, and discharged wastewater.