The comparative analyses of structural and electrical properties of Ag(Ta0.5Nb0.5)O-3 and Ag(Ta0.8Nb0.2)O-3 thick films have been investigated. Ag(Ta0.5Nb0.5)O-3 and Ag(Ta0.8Nb0.2)O-3 thick films have been prepared by screen printing method on the alumina substrates and sintered at 1150 degrees C and 1140 degrees C for 2 h, respectively, due to their different sintering temperature. The dielectric properties of Ag(Ta0.5Nb0.5)O-3 and Ag(Ta0.8Nb0.2)O-3 thick films were measured from 1 kHz to 1 MHz. The voltage dependent leakage current behavior of Ag(Ta0.5Nb0.5)O-3 and Ag(Ta0.8Nb0.2)O-3 thick films were investigated at the temperature range from 30 to 100 degrees C. The Ag(Ta0.5Nb0.5)O-3 and Ag(Ta0.8Nb0.2)O-3 thick films has negative temperature coefficient resistivity properties. The dielectric properties and ac conductivity have been investigated at temperature range from 30 to 120 degrees C with varying the frequencies (10 kHz-1 MHz). The activation energy for conduction process was calculated from the slope of ac conductivity. (C) 2010 Elsevier B.V. All rights reserved.