Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Polymeric surfaces obtained by chemical vapor deposition of HMDSO on aluminum plates using plasma were modified by means of low pressure Argon plasma and vacuum ultraviolet radiation (VUV). The polymeric surface was directly exposed to the plasma -which also acted as a vacuum ultraviolet radiation source- at different conditions. An important contribution of the VUV radiation component in surface modification was observed. The surface free-energy, the chemical composition, and the morphology of the films were determined by contact angle measurement, FTIR spectroscopy, and SEM. It was observed that the action of VUV radiation inside de Argon plasma was responsible for more than 45% of the increase of surface freeenergy, and that the influence of VUV radiation on surface free-energy varied significantly as consequence of different exposure times.4211925Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)