Dense samples of Ce0.9Gd0.1O2-delta with grain sizes in the range 91-252 nm were prepared and their electrical properties studied by impedance spectroscopy. It was found that the bulk conductivity is not affected by grain size or atmosphere and that small grain sizes lead to a larger total resistance of the material. The most striking result corresponds to a sample sintered in wet air that exhibited electrical characteristics that hint clearly at the presence of proton conduction at temperatures below 200 A degrees C.