ZrO2 films have been prepared by RF reactive sputtering using different substrate-target distances and RF powers. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical spectroscopy. Both monoclinic and tetragonal phases have been found in the films. All the films show a random orientation. The crystallite size increases as the substrate-target distance decreases and the RF power increases. It has been found that the residual stress of the films is mainly caused by the intrinsic stress. Also, the influence of substrate-target distance and RF power on the optical properties of the films has been discussed.