The structural, morphological and electrochemical properties of the hydrothermally prepared manganese oxide (MnO2) nanostructures are discussed in this paper. Interesting 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 132m2 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 168Fg−1. In addition, the synthesized nanomaterial showed a good reversibility and cycling stability.