The structural, morphological and electrochemical properties of the hydrothermally prepared manganese oxide (MnO2) nanostructures are discussed in this paper. tnteresting nanostructures of MnO2, mixture of nanostructured surface with a distinct plate-like morphology and nanorods, have been prepared by employing hydrothermal synthesis under mild conditions. The specific surface area of the prepared material was 132 m(2) g(-1). Electrochemical properties of the synthesized nanostructured material were studied using galvanostatic cycling and cyclic voltammetry in a mild aqueous electrolyte that showed a high specific capacitance of 168 Fg(-1). In addition, the synthesized nanomaterial showed a good reversibility and cycling stability. (c) 2006 Elsevier B.V. All rights reserved.