This study aims at a more detailed simultaneous investigation of the bulk, grain boundary and electrode reaction behaviour of yttria stabilized zirconia (YSZ) by the technique of the differential impedance analysis (DIA). The experiments are performed on both single crystal and polycrystalline samples in a wide temperature interval-from 200 to 950 degrees C. For improvement of the measurement accuracy at high temperatures, a procedure for correction of the parasitic inductance is introduced. (c) 2005 Published by Elsevier Ltd.