An assessment of the role of the design and operating parameters on the performance of solid breeder blankets based on lithium ceramics (Li2O and γ-LiAlO2) was carried out. The results indicate that not only poor thermophysical properties but also uncertainties associated with the property data base are the design-limiting f actors. In addition, the operating conditions such as the upper and the lower temperature limits, the choice of breeder materials either in the form of sintered pellets or in sphere-pac form, the interfacial contact resistance between the coolant channels and the solid breeder, and the diffusion characteristics of tritium and chemical interactions between tritium and the solid breeder play a prominent role in selection of blanket concepts. Designs to account for the expected degradation of the thermophysical properties due to thermal sintering and nuclear irradiation lead to high coolant and structural material fractions, and thus may result in a lower tritium breeding ratio. The results of the parametric studies show that water-cooled solid breeder blanket designs require a firmer data base for the operating temperature limits, the thermophysical properties, the gap conductances, and the tritium retention and release characteristics of solid breeders.