The blend of sol-gel processing and electrospinning technique, yields composite nanofibers of poly(vinyl alcohol) (PVA)/zinc acetate/copper acetate. Calcining these fibers resulted in nanocomposite fibers of ZnO/CuO with diameters of 50-100 nm which was revealed by the scanning electron microscope images. Energy dispersive X-ray analysis (EDX) confirmed the presence of the ZnO/CuO composite. The synthesized materials have been also characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible-near-infrared spectroscopy (UV-vis-NIR) and powder X-ray diffraction (XRD). From the UV spectra, the band gap of the nanocomposite was calculated to be 3.1 eV. Dielectric properties of these samples at different temperatures were studied with respect to frequency. The second harmonic generation efficiency of the material was found to be 11.1 times that of potassium dihydrogen orthophosphate (KDP). (C) 2010 Elsevier B.V. All rights reserved.