Nanocrystalline SnO 2 particles have been synthesized by a sol-gel method from the very simple starting material granulated tin. The synthesis leads a sol-gel process when citric acid is introduced in the solution obtained by dissolving granulated tin in HNO 3. Citric acid has a great effect on stabilizing the precursor solution, and slows down the hydrolysis and condensation processes. The obtained SnO 2 particles range from 2.8 to 5.1 nm in size and 289-143 m 2 g -1 in specific surface area when the gel is heat treated at different temperatures. The particles show a lattice expansion with the reduction in particle size. With the absence of citric acid, the precursor hydrolyzes and condenses in an uncontrollable manner and the obtained SnO 2 nanocrystallites are comparatively larger in size and broader in size distribution. The nanocrystallites have been characterized by means of TG-DSC, FT-IR, XRD, BET and TEM.