Dimethylamine borane (DMAB) electro-oxidation in alkaline media was studied using static and rotating gold single-crystal electrodes in the hanging-meniscus configuration. DMAB oxidation showed a strong sensitivity towards surface structure on gold electrodes. In situ Fourier transform infrared (FTIR) spectroscopy revealed that the potential-dependent cleavage of the B–N bond is one of the initial steps of the oxidation process. FTIR also showed that dimethylamine is oxidised in the potential range of gold oxide formation.