The electrochemical properties of the Bi-Ru pyrochlore Bi2Ru2O7-y in acid and acid methanol solutions have been studied. Surface analysis using scanning electron microscopy, energy dispersive X-ray analysis and X-ray photoelectron spectroscopy demonstrate the surface of the material to be stable to anodic polarization in H2SO4. The higher stability of this material compared with Pb2Ru2O7-y and Bi2Ru2O7+y is rationalized in terms of the lack of appreciable amounts of oxygen defects in the structure.