ZnO nanofibers were fabricated by an electrospinning method using a solution containing sol-gel precursors, polymer and solvent. The as-spun and annealed ZnO/poly(4-vinyl phenol) composite fibers were characterized both structurally and electrically. The composite fibers were completely decomposed to obtain polycrystalline ZnO nanofibers. The crystallinity of ZnO nanofibers improved with increase in annealing temperature. The diameters of ZnO nanofibers after annealing above 600 degrees C ranged from 35 nm to 100 nm. The activation energy of ZnO nanofibers for electrical conduction was inversely proportional to the annealing temperature. The ZnO nanofibers showed CO gas sensing capacity at concentration as low as 1.9 ppm. (C) 2009 Elsevier B.V. All rights reserved.