Tungsten-doped titanium-dioxide (W-TiO 2 ) nanoparticles are successfully synthesized using a multiple-diffusion-flame burner with a separate center tube. Vaporized titanium tetra-isopropoxide (TTIP) precursor issues from a center tube to produce TiO 2 nanoparticles, while a tungsten mesh, suspended above the surrounding multiple over-ventilated hydrogen diffusion flames, serves as the solid-phase metal doping source. At a lower tungsten loading rate, W-TiO 2 nanoparticles are generated, as indicated by an obvious angle shift of 0.15 for the entire x-ray diffraction spectrum. However, at a higher tungsten loading rate, homogenous nucleation of WO x occurs before or concurrently with TiO 2 nucleation, producing mixed nanopowders, permitting fewer tungsten ions to be doped into TiO 2 . Ultraviolet-visible spectroscopic characterization reveals that the as-synthesized W-TiO 2 nanoparticles possess augmented absorbing ability in the visible-light wavelength range, where the band gap is reduced from 3.20 to 3.05 eV, compared with that for the nondoped TiO 2 nanoparticles.