Thin films of La0.6Sr0.4CoO3−δ (LSC) were deposited by flame spray deposition at a deposition temperature of 200°C. The as-deposited LSC films were dense, particle-free and amorphous. Upon annealing above 600°C, the films crystallized into the rhombohedral perovskite LSC phase. For isothermal annealing at higher temperatures parabolic grain growth kinetics occur in parallel to densification of the thin films. Electrochemical measurements on symmetrical cells with LSC films on CGO pellets showed lowest area specific resistance (ASR) of 0.96Ωcm2 at 600°C for films of 38nm in grain size annealed at 700°C. Degradation of the ASR of the LSC films of 3.9% was found after 5 days operation at 550°C in ambient air.