The performance characteristics of fuel cells based on proton conducting BaCeO3 solid electrolyte doped with europium is reported. Fuel cells were operated for up to 200 h with both hydrogen and ammonia individually as fuel. Results show that the performance of the cell is the same irrespective of the fuel used. The open circuit voltage of the cells was lower than the theoretically expected value due to the presence of significant electronic conduction. Nevertheless, the data show that a fuel cell incorporating a europium doped barium cerate electrolyte operated on ammonia fuel is a viable alternative to fuel cells utilizing hydrocarbon fuels as sources of hydrogen. Crown Copyright (c) 2006 Published by Elsevier B.V. All rights reserved.