Ultrafine TiO 2 particles have been synthesized successfully by a facile gas flame combustion method. The synthesized sample is characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), and photoluminescence (PL) spectroscopy. The as-prepared TiO 2 nanoparticles appear to be a single anatase crystalline phase and the diameter is about 9 nm. Besides a sharp emission at 398 nm originating from the radiative annihilation of excitions, a weak broad band at about 434 nm from the defect-related emission is also discussed.