10 mol% titania doped YSZ samples were prepared by high temperature firing of mixtures of YSZ and TiO2. The role of firing time (2 to 16h) and temperature (1300 to 1600 degrees C) on the low temperature electrical behavior in air was found significant. For samples sintered for 2h at different temperatures, the grain boundary conductivity increased with firing temperature. For samples sintered at constant temperature (1500 degrees C) the grain boundary conductivity increased with firing time up to about 8h. The role of grain boundaries on the high temperature electronic conductivity under reducing conditions was found negligible when compared to the low temperature data in air, suggesting that at high temperature the overall conductivity is determined by the bulk grain behavior.