A protein based electrochemical sensor for the detection of hydrogen peroxide based on Myoglobin immobilized on gold nano structures patterned on Indium tin oxide electrode was developed. A uniformly distributed nanometer sized Au-array on ITO electrode surface was obtained by optimizing electro deposition conditions. The morphology of Mb molecules and Au-nanostructures on ITO was investigated by scanning electron microscopy. A Cyclic voltammetry technique was employed to study electrochemical behavior of immobilized Mb on Au/ITO electrode. From CV, a pair of quasi-reversible redox peaks of Mb obtained in 10 mM PBS buffer solution at 0.28 and 0.11 V respectively. From the electrochemical experiments, it is observed that Mb/Au/ITO electrode provides a facile electron transfer between Mb and modified ITO electrode and it also catalyzes the reduction of H2O2. A linear increase in amperometric current with increase in H2O2 concentration was also observed. The stability, reusability and selectivity of the biosensor were also evaluated. The proposed biosensor exhibits an effective and fast catalytic response to reduction of H2O2 which can be used in future biosensor applications.