A simple solution growth route has been employed to synthesize nanocrystalline cobalt oxide thin films on glass substrates, The obtained films were characterized by X-ray diffraction and FTIR spectroscopy. The as-deposited films were identified as a mixture of different phases of Co(OH)(2), while the annealed ones as Co3O4. The absorption of the annealed films gradually decreases with an increase of the wavelength in the 310-820 nm region, Upon annealing, the absorption coefficient decreases. The calculated band gap energy from optical absorption data for annealed films is 2.2 eV. The as-deposited thin films are dielectric, while the post-deposition heat-treated ones are characterized by resistivity of several M Omegas/cm(2) at room temperature.