The transport of a trivalent chromium ion through charged polysulfonated cation-exchange membranes in the presence of metals of different valences under Donnan dialysis conditions was studied as a function of pH gradient at 25°C. The recovery factor (RF) values of chromium ion were obtained, and it was found that the RIF values decreased with the increasing of the metal valence. The transport of chromium ions through membranes was correlated with the flux data, which depended on the metal valences as well as the structure of the membrane. It was observed that the transport was influenced with H+ ion concentration in the receiver phase. © 2004 Elsevier B.V. All rights reserved.