Elastic Recoil Detection Analysis (ERDA) technique with H-1(alpha,alpha)H-1 forward scattering was used at 3.0 MeV to analyze hydrogen in corrosion product films formed on molybdenum and niobium surfaces at selected potentials of the anodic and cathodic potentiodynamic scan. Hydrogen in the corrosion film on molybdenum was found to be linearly increasing with the polarizing potential. On the other hand, niobium film is found to be less permeable to hydrogen in the active region compared to the passive region of the voltammogram.