Rates of electropolishing of vertical copper plates in phosphoric acid using a gas sparged rectangular cell were measured under different conditions of superficial gas (N-2) velocity, workpiece height, physical properties of the solution and macroroughness of the surface. The limiting current was found to increase with increasing N-2 superficial velocity to the power of 0.24 while increasing workpiece height (L) was found to decrease the limiting current (I) according to the equation, I=aL(-0.19). The data were correlated by the equation j = 0.235(Re Fr) (-0.253)(L/d(e)) (-0.19) Where j, Re and Fr are the mass transfer j factor, Reynolds number and Froude number, respectively Macroroughness was found to increase the limiting current by a modest amount depending on the peak-to-valley height of the roughness elements. The economic importance of using gas sparging in mass transfer controlled metal finishing processes is pointed out.