A series of TiO2-ZrO2 mixed oxide samples with various ZrO2-TiO2 content (10, 30, 40, 60, 70 and 90 mol %) were prepared by hydrothermal method. These nanocomposites were characterized by XRD, SEM, UV-vis spectroscopy and Photoluminescence spectroscopy. XRD data identified Anatase and Rutile phases in the TiO2 rich samples while Tetragonal and Monoclinic phases in ZrO2 rich samples. The average crystallite size of the samples was between 9 to 26 nm. As per Uv-Vis spectra, the band gaps of TiO2-ZrO2 composites vary from 1.34 eV to 2.48 eV. The absorption spectra show a shift of the absorption edge of TiO2-ZrO2 towards longer wavelength region. The decreased band gap is attributed to the surface trap states. The PL spectrum shows very strong blue-green PL band under excitation at 300 nm. The occurrence of emission peaks in the visible region is attributed to the presence of defect levels below the conduction band.