The effect of sodium molybdate in inhibiting galvanic corrosion of Zn coating and mild steel is addressed. The inhibitor's performance was appraised by Zero Resistance Ammeter on HDG/mild steel galvanic coupling model in 0.05 M NaCl (+5 mM Na₂MoO₄) media. The effectiveness of Na₂MoO₄ was evaluated on HDG substrate mechanically scratched to reach the steel. Scanning Vibrating Electrode Technique was employed for assessing the distribution of j from scribed HDG surfaces. This local electrochemistry approach was repeated in NaCl solution to examine the behaviour of HDG when the Zn-coating is partially removed. Surface analysis supported all electrochemical results.