Using concentric-cylinder, blade-vane, and parallel-plate viscometers, reliable quantitative rheological results (yield stress, apparent viscosity, etc.) of simulated nuclear waste slurry are obtained. Concentric-cylinder and parallel-plate geometries were used to measure shear stress versus shear rate. Precautions required to avoid Taylor vortices and the correction of wall slip were addressed. The blade-vane geometry was used for direct measurement of yield stress and compared with extrapolated values obtained from the concentric-cylinder and parallel-plate measurements. Consistent results were obtained with these different laboratory viscometers.