A new synthetic route to obtain high-purity strontium titanate, SrTiO3, using the sol-gel-hydrothermal reaction of TiCl4 and a SrCl2 solution in an oxygen atmosphere has been developed. In the synthesized products the SrTiO3 nanoparticles are nearly spherical and decrease in size with the reaction time (48 h) down to a diameter of about 40 nm. The microstructure and composition of the as-synthesized samples were investigated by X-ray diffraction (XRD), high-resolution TEM (HRTEM), Raman spectroscopy, atomic force microscopy (AFM), and energy-dispersive X-ray spectroscopy (EDX). All the samples were identified as cubic perovskite phase.