Well-dispersed aqueous slurries of fine ceramic powders with high solids loading are often required for various shape forming techniques such as slip and tape casting in order to fabricate advanced ceramics with a dense and uniform microstructure. Colloidal processing of lead lanthanum zirconate titanate (PLZT) powders was conducted at various pH using ammonium polymethacrylate as a dispersant. Suspensions were characterized by viscosity and zeta-potential measurements. The effect of pH on polymer adsorption and the rheological behavior of the slurries were investigated and stabilization mechanisms discussed. Through optimization of the dispersant concentration and pH, solids loadings of the suspensions up to 50 vol.% with a relatively low viscosity were obtained.