NiO nanowires were successfully prepared via a wet chemical method. The nanowires are single and crystalline with the growth direction along [111] axis. Transmission electron microscopy and X-ray diffraction were employed to characterize the structural features of NiO nanowires. Infrared spectra indicated the characteristics of NiO nanowires and some other atomic arrangements, during the high-temperature decomposition. (C) 2003 Elsevier Science B.V. All rights reserved.