The electroosmotic flux through a cation-exchange membrane has been obtained in different situations. From these measurements, the apparent electroosmotic permeability, W, of a cation-exchange membrane has been determined as a function of the temperature, T, and the stirring rate, v, of the solutions. In all the experimental situations studied, W decreases when v increases, while it can increase or decrease with T depending on the temperature range considered. For this last reason, the (T,W) curves show a minimum whose value and position depend on the experimental conditions established. The influence of the concentration polarization effect in the value of W and in its dependence with v and T is studied and quantified.