The article describes the modern problems of formation and purification of marine oil-containing waters. The efficiency of using electrocoagulation to remove oil from water-oil emulsions of different mineralization using aluminum and iron anodes was studied. Treatment of water-oil solutions with an oil content of 100 mg/dm3 by electrocoagulation in a single-chamber electrolyzer provides 98–99 % oil removal using these electrodes at an anode current density of 0.57–2.11 A/dm2 for highly mineralized waters and 0.34 A/dm2 for freshwater treatment during the first 15 minutes provides a reduction in oil concentration from 100 mg/dm3 to values at the level of 1.55–2.93 mg/dm3. When extending the water treatment time to 45 minutes, greater efficiency in highly mineralized waters is provided by the aluminum anode