The rheological behaviour of alumina/platelets (Al2O3 or SiC) suspensions has been established by measuring zeta potential versus pH and the relative viscosity as a function of pH, solids loading and platelets content. Highly homogeneous mixtures of alumina/platelets, with different platelets content (5, 8, 1 2 and 20 vol %), have been obtained by controlled flocculation at a pH value in the range 6-7. From these powders, very close to theoretical density (greater-than-or-equal-to 99% d(th)) and slightly oriented platelet-reinforced alumina compacts have been obtained by hot pressing at temperatures ranging from 1500-1550-degrees-C.