Nanocrystalline SnO2 oxides particles have been successfully synthesized via polyol process using diethylene glycol (DEG) as a solvent, followed by powder thermal treatment. The general applicability of the process is shown and the advantages in terms of properties and processability are described. The powders thus prepared were investigated using X-ray diffractometry. (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence spectra (PL). The X-ray diffraction patterns of the samples were indexed to the rutile phase for SnO2.The TEM images show uniform isotropic morphologies with average sizes close to10 nm. This decrease in particle size is accompanied with a decrease in the band-gap value from 3.55 eV for SnO2 down to 3.27 eV as shown by UV-visible spectra. It is demonstrated that the crystallite size less than 10 nm can be controlled by changing the quantity of added water (rate hydrolysis h=n H2O/n Metal).