La0.95Sr0.05CoO3 pellet has been prepared using sol-gel process followed by high temperature sintering and subsequent annealing. The thermoelectric performance was carefully studied from room temperature to 750 K. At room temperature, La0.95Sr0.05CoO3 has a respectable Seebeck coefficient of 252 mu V/K. With increasing temperature, both electrical resistivity and thermopower decrease. The conduction behaviors of La0.95Sr0.05CoO3 Were explained in terms of small polaron hopping mechanism, in which the transport carriers are positive polarons (Co-Co3+(4+))(center dot). The dependence of electrical resistivity and thermopower on temperature could be attributed to the transition of the Co3+ into Co4+ and the increase of the (Co-Co3+(4+))(center dot) concentration on the Co sites. (c) 2005 Elsevier B.V. All rights reserved.