The tin-modified platinum and palladium-deposited gold (Sn/Pt and Sn/Pd/Au) electrodes have exhibited a higher electrocatalytic activity for the reduction of nitrate than any electrode so far reported in the literature. Ammonium ions were predominantly formed on Sn/Pt, while N2O and/or N-2 were the most likely main products on Sn/Pd/Au.