Synthesis of nitrogen (N) doped zinc oxide (ZnO) has been attempted by a serial operation of co-grinding the mixture of ZnO and urea (CO(NH2)(2)), followed by calcining the ground product at 400 degrees C. The prepared ZnO sample has been characterized by X-ray diffraction (XRD) analysis, infrared spectroscopy (IR), Raman spectroscopy. All spectra from these techniques are completely different from those of the hand ground mixture sample, confirming the mechanochemical effect of N-doping. The prepared N-doped ZnO sample exhibits light absorbance in the visible light wavelength region, and has high photo-catalytic ability in an anti-bacterial test. (c) 2006 Elsevier B.V. All rights reserved.