The reduction of ubiquinone-10 adsorbed onto a gold electrode in borax and sodium hydroxide solutions has been studied by subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS). A reorientation of the adsorbed ubiquinone molecule on reduction could be observed. The SNIFTIRS spectra show that the molecule is anchored to the electrode surface through the isoprenoid groups, with the quinone ring away from the surface. Upon reduction, the aromatic ring formed is adsorbed by pi interactions with the metal surface and is aligned flat to the surface, slightly lifting the isoprenoid chains.