Vanadium dioxide (VO2) undergoes a Mott metal-insulator transition (MIT) close to room temperature, and has been suggested as a candidate for use in smart window and adaptive infrared camouflage.Here we report the synthesis of uniform free-standing VO2 nanowires using a simple hydrothermal method.These nanowires have typical diameters of 150±30 nm and lengths up to >10 μm.Scan electron microscopy and X-ray diffraction measurements show that the VO2 nanowires are uniform and exhibit a monoclinic structure.Moreover, phase transition properties of VO2 nanowires were monitored via variable temperature X-ray diffraction method and differential scanning calorimetry.These VO2 nanowires should provide promising materials for fundamental investigations of nanoscale metal-insulator transitions.