Synchrotron Far Infrared Reflectance Spectroscopy (SFIRS) has been used to study the adsorption of oxyanions at a gold thin-film electrode. Surface-adsorbate vibrational frequencies of 240 and 255 cm(-1) have been measured 'in-situ' in acid solutions of 0.5 M HClO4 containing 0.05 M Na2SO4, and Na3PO4, respectively. It was observed that in the presence of Br-, competitive adsorption occurs such that phosphate is displaced from the electrode surface and the current-potential behavior of the electrode is determined by the more strongly adsorbed Br- anion. In 0.1 M NaClO4 at neutral pH, no interaction between the oxyanions and the gold surface could be observed and the intensity of Au-Cl- vibration was about 5 times weaker than in acid. Adsorption of OH was found to be the dominant interaction, inhibiting sulfate adsorption, in 0.05 M Na2SO4 + 0.1 M NaClO4 solution. The latter finding is similar to results obtained by others on the inhibition of sulfate adsorption on Ag by OH-.