A facile and rapid microwave-assisted combustion method (MWAC) was developed to synthesis to produce nanocrystalline ZnO powder using dissolution of zinc nitrate (as the oxidant) and urea (as fuel) as the starting materials and water as solvent, then heating the resulting solution in a microwave oven. The study suggested that application of microwave heating to produce the homogeneous porous ZnO was achieved in a few minutes. The structure and morphology of the as-prepared combustion products were investigated by means of X-ray powder diffraction (XRD), Fourier transform infrared spectra (FTIR), Raman spectra, UV-Vis absorbance spectra and Scanning electron microscopy (SEM). The XRD, FTIR and Raman spectra confirmed the formation of hexagonal wurtzite structural ZnO and the SEM results indicated the porous surface characteristic of the products. The as-prepared powders have larger band gap energy (3.06 eV) and are described here. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.