The densification behavior and grain growth of Ce0.8Gd0.2O1.9 ceramics were investigated with the gallia concentration ranging from 0 to 10 mol%. Both the sintered density and grain size were found to increase rapidly up to 0.5 mol% Ga2O3, and then to decrease with further additions. Under the same sintering conditions, the samples with 3 mol% Ga2O3 and less exhibited a higher sintered density, as compared to the one without Ga2O3 addition. However, a pinning effect on grain growth was found at >= 2 mol% Ga2O3. In the dopant content range of 0 to 10 mol%, 0.5 mol% Ga2O3 was the optimum doping level in promoting densification and grain growth of commercially available powders of Ce0.8Gd0.2O1.9. (C) 2005 Springer Science + Business Media, Inc.