Single-crystalline alpha-MnO2 nanowires with diameters of 10-30 nm and lengths to several micrometers have been successfully synthesized by hydrothermally treating a mixed solution of Mn2O3 and KOH at 180 degrees C for 24h. The morphology and the crystal structure of the final products were characterized. The cyclic voltammetry curve of the products indicated that the alpha-MnO2 nanowires are promising electrode material for applications in super capacitors. The specific capacity of the electrode deduced from the cyclic voltammograms curve is 185 F g(-1). The magnetic properties of the products have been evaluated using a vibrating magnetometer and results show that the alpha-MnO2 nanowires exhibit ferromagnetic characteristics at room temperature. (c) 2006 Elsevier B.V. All rights reserved.