The purpose of the present work is to provide further information on concentration polarization and fouling of a Cation Exchange Membrane (CEM). This is undertaken by means of the voltamperometry technique to yield the characteristics of current-voltage curves. The deduced data of the limiting current density (LCD) and transmembrane resistances are discussed with respect to the concentration, mass, and charge of the counter-ion. Three graphical methods are used to determine the values of the LCD. They are, namely, Cowan-Brown, Derivative and Cross section of tangents methods. The fouling of the CEM is made in evidence using the foulant cationic surfactant Hexadecyltrimethylammonium chloride (CTAC). The values of the LCD and resistances show that the effect of this foulant is more pronounced on CEM than AEM, as a result of the signs of their functional groups.