Electrochemical oxidative degradation of polypyrrole (PPy), known as overoxidation, in aqueous media has been studied using Raman and FT-IR spectroscopy. Raman spectroscopy was found to be the more sensitive tool to monitor the overoxidation reaction and it was found that PPy degrades at potentials as low as +0.5 V versus the saturated calomel electrode, in the presence of chloride ions. The rate of overoxidation of PPy is higher at higher potential and at higher pH. (C) 1998 Elsevier Science S.A. All rights reserved.