  We report thermoelectric (TE) properties of Sr and Mn co-substituted LaCoO3
system from room temperature to 700 K. Sr-substitutions at La and Mn at Co site
in LaCoO3 improves the electrical conductivity ({\sigma}). Thermal conductivity
(\k{appa}) of all the samples increases with the increase in temperature but
decreases with the substitution in LaCoO3. An estimation of the electronic
thermal conductivity (\k{appa}e) suggests a dominant phonon contribution to
thermal conductivity in this system. A maximum value of the figure of merit is
0.14 at 480 K for La0.95Sr0.05Co0.95Mn0.05O3
