Nanostructured PbO2 obtained by hydrolysis of Pb(CH3COO)(4) is shown to exhibit an excellent electrochemical activity as a thin electrode in lead-acid cells. This material was characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and Brunauer-Teller-Emmett measurements. The electrode was prepared by spray deposition of the nanostructured PbO2 material and showed high utilization (about 65% of the theoretical capacity! and good cycling stability at discharge current of 1 C. It is suggested that the nanostructure is the key factor for the enhanced electrochemical activity of lead dioxide. (C) 2004 The Electrochemical Society.