The study is focused on the use of hydrogen peroxide on cobalt electrowinning and its advantages over conventional electrowinning cell practices. The current efficiency increased slightly to an optimum concentration of H2O2, under fixed electrowinning conditions of current density-200Amp/ m2, pH-3, Co2+-45g/L and separation of electrode by 50mm. Further increase of additive concentration resulted in decreasing values of current efficiency. SEManalysis, DSC analysis and X-ray diffraction pattern indicated improved microstructure with the hcp lattice of cobalt metal in presence of hydrogen peroxide. The improved microstructure resulted in improved microhardness. The addition of H2O2 also resulted in formation of less or no sludge and the mechanism for the same is proposed on basis of the cyclic voltametry.