In this work, composite cation-exchange membrane was prepared by chemical polymerization of pyrrole on the surface of the poly(vinylidene fluoride) (PVDF) membrane using ferric ions. The changes in the surface morphologies of non-modified and polymer-modified PVDF membrane were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The ion-exchange capacity, water uptake, and fixed group concentration of the composite membrane were investigated. The polypyrrole/PVDF composite membrane was used for the removal of copper (II), chromium (III), iron (III), and aluminum (III) ions from aqueous solution with Donnan dialysis experiments. The flux values (J) and recovery factors (RF) of Cu(II), Cr(III), Fe(III), and Al(III) were obtained. Because of the smaller ion charge and hydration volume, the transport of the Cu(II) ion is higher than that of the other metals. Copyright (c) 2011 John Wiley & Sons, Ltd.