In recent years, the synthesis of one-dimensional nanomaterials has assumed considerable importance because of the potential applications of these nanomaterials especially in nanodevices. In this study, bundled tungsten oxide (W18O49) nanowires having diameters of 25-60 nm and lengths of several micrometers were fabricated on Si substrates within 1.5 min by microwave plasma-enhanced chemical vapor deposition (MPECVD). The crystal structure, morphology, and chemical composition of these nanowires were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and cathodoluminescence (CL) spectrometry. The growth of the W18O49 nanowires occurred along the [010] plane. Because no catalysts were used, it was suggested, and then analytically confirmed, that the vapor-solid mechanism was suggested for this growth process; this has been confirmed analytically. An orange emission was observed in the CL spectra, suggesting that the W18O49 nanowires exhibited a redshift, resulting from the presence of significant O deficiencies. In this manner, our overall results demonstrate that MPECVD is a highly effective and suitable method for the fabrication of W18O49 nanowires. (C) 2010 The Electrochemical Society. [DOI:10.1149/1.3459906] All rights reserved.