Multi-walled-carbon-nanotubes/polyvinylacetate/titanium oxide (MWCNTs/PVAc/TiO2) composite fibers with different MWCNT loadings were prepared using the electrospinning technique. The addition of cetyl trimethyl ammonium bromide (CTAB) as a surfactant agent to promote the dispersion of the MWCNTs was also evaluated. The morphological and microstructural properties of as-spun and annealed samples in air at 600 degrees C were examined using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The sensing characteristics of the synthesized TiO2-based nanostructures were evaluated for oxygen monitoring at moderate temperatures. The effects of the MWCNT loading, the addition of the surfactant and the composition of the TiO2 crystalline phases were investigated and discussed.