Physicochemical compatibilities of the series of LaFeO3 base perovskites La(0.6)Sr(0.4)Fe(0.8)M(0.2)O(3-delta) and (La0.6Sr0.4)(0.9)Fe(0.8)M(0.2)O(3-delta) (M=Cr, Mn, Co, Ni) with the solid electrolyte yttria stabilized (8 mol% Y2O3) cubic zirconia, 8YSZ, were investigated. Powder mixtures of the perovskites with 8YSZ were annealed at 1000 degrees C for time periods up to 1300 h. The quenched samples were analyzed by XRD and SEM/EDX for identifying the reaction products. The results provide a working hypothesis for the development of improved compositions of cathode materials in solid oxide fuel cells.