Nanocrystalline tin oxide (SnO2) powders have been synthesized by a low temperature chemical precipitation method. As-prepared and heated powders were characterized by XRD, SEM and luminescence studies. Crystallographic parameters such as crystallite size, lattice parameters and dislocation density in SnO2 nanocrystalline powders were calcu- lated by Rietveld analysis. The average crystallite size of 9 - 43 nm was obtained for SnO2 powders through controlled heat treatment process. The washed powders morphology was almost spherical in shape and average agglomerate crystal size was between 0.2 - 0.4 μm. A Photoluminescence (PL) study was measured at an excitation wavelength of 265 nm for as-prepared and annealed powders; it showed a broad emission peak at 417 nm for all powders. The highest PL emission was attained for the powder annealed at 500℃. The synthesized nanocrystalline SnO2 oxide semiconductor material could be suitable for making optoelectronic and sensor devices.