Anode-supported solid oxide fuel cells consisting of nickel gadolinium doped ceria (NiO-CGO, 60:40 wt%) anode, gadolinium doped ceria (CGO) electrolyte and lanthanum strontium cobaltite ferrite gadolinium doped ceria (LSCF-CGO) cathode are developed and operated under single-chamber conditions, utilizing methane/air mixture. The cell performance is optimized regarding the electrolyte microstructure, cathode composition and testing conditions. The performance of the cell improves with the decrease of the thickness of the electrolyte and the increase of the ratio of methane to oxygen. The test cell with LSCF-CGO cathode (70:30 wt%) that was sintered at 1100 degrees C for 2 h and 150 mu m dense electrolyte exhibits the maximum power output of similar to 260 mW cm(-2) at 600 degrees C in CH4/O-2 = 2 atmosphere. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.