The optical properties of the perovskite-type NaTaO3 synthesized from sol-gel (SG) and solid-state (SS) methods were studied by absorption and photoluminescence (PL) techniques. We observed significant PL emission at room temperature from the SS NaTaO3, while the emission was negligible from the SG NaTaO3. Variation of the PL intensity and peak position with temperature demonstrated that the recombination of the localized exciton Ta4+ -O- in the regular TaO6 octahedra was the origin of the luminescence in NaTaO3. The Ta-O-Ta bond angle affected the delocalization of the excitons and thus, the PL behaviors of NaTaO3. (c) 2007 The Electrochemical Society.