The effect of thermal treatment on the structure and electrical characteristics of La1-xSrxFe1-yCoyO3-delta (LSCF) electrodes on Ce0.9Gd0.1O1.95 (CGO) electrolytes has been investigated. Low calcination temperatures and short sintering times leads to the formation of a cubic A-site deficient perovskite, with the composition La0.6Sr0.13Co0.2Fe0.8O2.52, which exhibits a low electrode resistance. Higher calcination temperatures and longer sintering times leads to the incorporation of strontium, derived from the decomposition of SrCO3, into the perovskite structure, producing a stoichiometric rhombohedral perovskite. Electrodes containing a larger proportion of the stoichiometric perovskite had a higher resistance than those consisting largely of the A-site deficient perovskite.