Reactively sputtered thin metal oxide films are used in the production of some electro-optic devices. To design and engineer such devices, knowledge of the physical characteristics of these films is essential. Investigations of the resistivity, reflection, and transmission properties of WOx and TaxOy thin films were done under a wide range of sputtering conditions. Reactive sputtering rates were determined for base argon pressures from 2.5 to 20 mTorr, O2 partial pressures from 0.5% to 50%, and power level from 2 to 8 kW. The maximum power density achieved was 34 W/cm2. Film thicknesses varied from 30 to 250 nm and were measured by a mechanical surface profile technique. Reflection and transmission characteristics and the corresponding optical constants were obtained from UV, visible, and near-infrared spectrophotometric scans of the films. The resistivities of the films were also measured, and they ranged from 101 to 108 Ω cm. The measured physical properties of these thin films were then related to the sputtering process parameters. Comparisons to corresponding evaporated metal oxide thin films indicate the differences in optical properties and resistivities.