Zinc oxide powders having hexagonal plate particles were prepared by homogeneous precipitation from boiling aqueous solutions that contained excess urea and 0.075 (Z075) and 0.300 (Z300) M Zn2+. The equilibrium, kinetic and thermodynamics of the adsorption of chromium (VI) from aqueous solution onto Z075 and Z300 were investigated. Thermodynamic parameters and K-# equilibrium constant of activation were calculated. Langmuir, Temkin and Dubinin-Radushkevich (D-R) isotherm models were used to describe the adsorption of Cr(VI) onto ZnO powders. The monomolecular adsorption capacity of Z075 and Z300 was determined as 980 and 1050mgg(-1) for Cr(VI), respectively.