Monodisperse and bimodal electrostatically stabilized polymer latices have been investigated with respect to shear viscosity and diffusion. The zero shear viscosity of monodisperse latices could be described by a recent model by Quemada that takes into account the order-disorder transition known from hard-spheres. The high shear viscosity of bimodal latices prepared by mixing monodisperse samples could be calculated from the data of the monodisperse latices by use of a model by d’Haene and Mewis. Diffusion coefficients in concentrated colloidal suspension were obtained by means of fiber optic quasielastic light scattering. With large particles short time self-diffusion was observed, but collective diffusion and long time self-diffusion were found in the case of small colloidal particles. In bimodal latices a probe diffusion of large particles in a matrix of small spheres was observed. Long time self-diffusion and probe diffusion showed a similar concentration dependence as reciprocal shear viscosity.