SrTiO3 precursor thin films were deposited on KBr single crystals and fused silica substrates by the sol-gel technique. Fourier transform-infrared (FT-IR) spectra, ultraviolet-visible spectra and X-ray diffraction spectra were recorded after the samples were cured at various temperatures. FT-IR spectra showed a gradual decrease in -OH concentration indicating removal of hydroxyls and reduction in peaks belonging to organic groups indicating the removal of organics. After annealing at 500 degrees C, the peak due to SrTiO3 crystallites (similar to 500 cm(-1)) began to appear, indicating crystallization. The optical spectra showed an increase in refractive index due to densification as the curing temperature increased. With increase in curing temperature, the thickness of the film decreased, indicating densification due to pore collapse. The optical band gap also changed with annealing due to the structural transformation from amorphous to crystalline phase. X-ray diffraction spectroscopy confirmed the structural changes.