Nanocrystalline SnO2 particles are prepared by thermal decomposition of tin citrate crystal. Distinction between the surface traps and lattice defects is carried out by the photoluminescence emission study, which gives two characteristic peaks at similar to 400 and 470 nm respectively. The peak at similar to 400 nm shifts toward the lower wavelength with increase of heat treatment because of decrease of defects. The intensity of peak at 470 nm due to the surface traps decreases with increase in particle size. Raman spectra exhibited new peaks, which are related to a surface layer of small crystals, and shift in peaks are found with different particle sizes. (C) 2008 Elsevier Ltd. All rights reserved.