Ultrafine-structure La0.65Sr0.35MnO3 (LSM) powders synthesized by self-propagating combustion method have been used to fabricate sensing electrodes (SEs) for NO2 mixed-potential sensors based on yttria-stabilized zirconia (YSZ). This type of sensor was found to provide better NO2 sensitivity at 500 A degrees C than sensors with LSM powders synthesized by traditional solid-state methods. The response values of the sensor have good linear relationship (sensitivity 36.6 mV/decade and linear fit 0.99) with the logarithm of NO2 concentration varying from 30 to 500 ppm. The influence of sintering temperature (1000, 1100, 1200, and 1300 A degrees C) on sensor response was also examined and was found to have a significant effect on the morphology of LSM-SEs. Moreover, in the presence of NO, CO2, CO, and NO2, the sensor exhibited good NO2 selectivity.