TiO2-ZrO2 mixed-oxide membranes were prepared via polymeric sol-gel technique. The final composition is already predefined during the preparation of the sols by using the corresponding quantities of the starting alkoxides. The mixed-oxide membranes were characterized by Xray diffraction, nitrogen sorption, and field emission scanning electron microscopy as well as filtration and corrosion tests. The observed results prove the positive influence on the investigated properties by addition of a second oxide. Depending on the composition of the mixed-oxide membranes, a remarkable increase in the crystallization temperatures is demonstrated. Using mixed-oxide systems, the retardation of grain growth is confirmed.