Co-DIM [DIM = 2,3-dimethyl-1,4,8,11-tetraazacyclotetradeca-1,3-diene], a Co(cyclam) analog, is reported to catalyze the electrochemical reduction of nitrate to ammonia. The Co(II)/Co(I) reduction of this compound in aqueous sodium bromide solutions was nearly reversible on pyrolytic graphite electrodes. The complex was catalytically active for reduction of NO3- as well as its reduction intermediates NO2- and hydroxylamine. Ammonia was the sole product found after electrolysis of sodium nitrate in the presence of Co-DIM on a carbon felt cathode.