Aligned alpha-Fe2O3 nanowires over large areas were successfully synthesized by oxidation of pure iron. Most of the assynthesized alpha-Fe2O3 nanowire arrays, grown vertically from the surface of the substrate, are perfect and single crystals with diameters of 20-40 nm and lengths of 2-5 mum. The high surface density of the nanowires (10(8)-10(9) cm(-2)) is considered to be responsible for the aligned growth. The size of the alpha-Fe2O3 nanowires may be tailored to required dimension by adjusting the flowing rate of the gases as well as the time and temperature of reaction. The aligned arrays of alpha-Fe2O3 nanowires reported here offered opportunities for both fundamental research and technological applications. (C) 2003 Elsevier B.V. All rights reserved.