Composite nanofibers containing nanometric TiO2 particles and multiwalled carbon nanotubes dispersed in poly(acrylonitrile) (PAN) were prepared by the electrospinning technique. The structure and quality of the precursor dispersions were evaluated by cryo-transmission electron microscopy. The fabricated nanofibers, the diameters of which were in the 20-200 nm range, contained well-oriented nanotubes and spherical TiO2 nanoparticles in close proximity. Such nanofibers are under investigation as new photocatalytic reactor elements.