In this study, shipyard oily wastewater treatment was investigated by electrocoagulation (EC) using aluminum electrodes in a batch reactor by evaluating different operation conditions. The maximum chemical oxygen demand (COD) removal efficiency of 88.83% was obtained at current density of 3 mA/cm(2). The removal efficiency was gradually improved with increasing current density and decreased with increasing COD concentration. However, initial pH value was not determinant factor for this process. Total energy and electrode cost were calculated as $0.88 per m(3) treated wastewater. The result of this research shows that EC process seems to be an efficient method for the oily wastewater treatment.