In this study tetragonal/cubic zirconia based composite electrolytes were prepared through stabilizer coating technique. Microstructures were characterized by XRD and SEM. The electrical properties were studied by impedance spectroscopy as a function of temperature. Results of electrical conductivity measurement proved that by increasing the 3YSZ content of the composite samples, the electrical conductivity at high temperatures (T > 550 degrees C) decreased while at low temperatures (T < 550 degrees C) the conductivity increased. It was shown that stabilizer coating is an attractive technique to prepare high performance solid electrolytes with improved electrical and mechanical properties with low level of consumed stabilizer. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.