ZrO2 films were deposited on silicon substrates at temperatures from 350 to 550 °C by metallorganic chemical vapor deposition (MOCVD) using zirconium acetylacetonates. Depositions were carried out at both atmospheric and low pressures. The optical properties, structure, microstructure, and composition of these films were characterized by Ellipsometer, X-ray diffraction, scanning electron microscopy (SEM), and electron spectroscopy for chemical analysis (ESCA), respectively. The deposition was kinetically controlled at low temperatures and mass transfer controlled at high temperatures. Use of zirconium (IV) acetylacetonate resulted in cubic ZrO2 with some carbon contamination whereas, tetragonal pure ZrO2 were obtained with the precursor zirconium (IV) trifluroacetylacetonate. The tetragonal ZrO2 films are fine grained and showed preferential orientation. The measured values of dielectric constant, refractive index, and electrical resistivity of ZrO2 films are 18, 2.0, and 5E13 Ohm.cm, respectively.