SrFe0.2-xTi0.8CoxO3-delta (x = 0.05-0.2) were prepared by solid-state reaction method. Phase characterization and lattice parameter evaluation were done by X-ray diffraction studies. Relative concentrations of iron in various oxidation states in these compositions were estimated using Mossbauer spectroscopy. Electrical conductivities of these bulk samples were measured in various ambient and temperatures using AC impedance spectroscopy. SrFe0.15Ti0.8Co0.05O3-delta and SrTi0.8Co0.2O3-delta have been found to exhibit good change in electrical conductivity between 21% O-2 and 10 ppm O-2 in argon. (C) 2008 Published by Elsevier Ltd.