Perovskite type LaCo(x)Fe(1-x)O(3) nanoparticles was synthesized by a sol-gel citrate method. The structural, electrical and sensing characteristics of the LaCo(x)Fe(1-x)O(3) system were investigated. The structural characteristics were performed by using X-ray diffraction (XRD) and transmission electron microscopy (TEM) to examine the phase and morphology of the resultant powder. The XRD pattern shows nanocrystalline solid solution of LaCo(x)Fe(1-x)O(3) with perovskite phase. Electrical properties of synthesized nanoparticles are studied by DC conductivity measurement. The sensor shows high response towards ammonia gas in spite of other reducing gases when x=0.8. The effect of 0.3 wt.% Pd-doped LaCo(0.8)Fe(0.2)O(3) on the response and a recovery time was also addressed.