The changes in surface structure of polyfaceted single crystal platinum spheres subjected to repetitive square-wave potential treatments in acid solution have been studied . The dependence of the prevailing type of change on symmetry, potential limits and frequency of the periodic potential has been determined. Results are discussed on the basis of different reactions occurring within definite potential windows and distinct rate controlling processes depending on the operating conditions. Accordingly, the surface restructuring involves a predominant change in either the real surface area, the crystallographic orientation or the entire surface morphology.