Two cationic polymers containing vinyl and quaternary ammonium groups were successfully grafted on silicone surfaces containing Si-H groups. The reaction was carried out by straightforward hydrosilylation reaction in water without using exogenous catalyst and without doping the surface with Si-H groups. The Si-H content was varied by changing the curing time or the ratio between silicone components. The surfaces obtained exhibited quaternary ammonium densities ranging from 1.8 x 10(14) to 2.8 x 10(15) charge/cm(2) and higher polarity and hydrophilicity in comparison with non grafted surfaces. Bactericidal effects of these surfaces against Escherichia coli and Staphylococcus epidermidis were evidenced. This study have evidenced also the fouling of the poly( quaternary ammonium) (PQA) surfaces by contact with plasmatic proteins probably limiting their use in some biomedical field (e.g. implantable medical devices). (C) 2015 Elsevier B.V. All rights reserved.