In this article, three dispersants including polyacrylic acid (PAA), an acrylic acid/acrylate ester copolymer, and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) were used to stabilize aqueous suspensions of nanosized Y-TZP powder. The interaction between the dispersants and the Y-TZP powder was characterized by measuring their adsorption isotherms. The influence of the dispersant on the zeta potential of the Y-TZP powder was also determined. The rheological properties of aqueous nanosized Y-TZP slurries with various solid loadings in the presence of different amount of dispersants were investigated at a constant pH of around 8.9. There was an optimum added amount for each dispersant, respectively. However, overdosage of the copolymer caused weaker flocculation than that of PAA. It was also found the optimum dispersant amount increased with increasing solid loading. Rheological measurements showed that PBTCA was the most effective one for deagglomeration control and viscosity reduction. (C) 2002 Elsevier Science B.V. All rights reserved.