Nanocrystalline La1-xSrxFeO3 (x = 0, 0.1, 0.2, 0.3 and 0.4) was prepared by sol-gel citrate method. The structural and microstructural characterization has been carried out with the help of X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. XRD studies confirm the formation of LaFeO3 with perovskite phase. Further studies by Fourier transform infrared spectroscopy were also conducted. DC electrical properties of the prepared nanoparticles were studied by D.C. conductivity measurements. The gas-sensing performance of the as-prepared La1-xSrxFeO3 nanoparticles was investigated towards different reducing gases like acetone (CH3COCH3), ethanol (C2H5OH), hydrogen sulfide (H2S), hydrogen (H-2) and liquefied petroleum gas (LPG). The nanocrystalline La0.7Sr0.3FeO3 exhibited good sensing performance towards acetone gas with rapid response and high sensitivity at 275 degrees C as compared with LaFeO3. (C) 2010 Elsevier B.V. All rights reserved.