Poly(ether-block-amide) (PEBA) films were grafted with acrylic acid (AAc) by gamma radiation, using the oxidative pre-irradiation technique. The effect of dose, monomer concentration, temperature, and reaction time on the graft percentage of AAc onto PEBA was studied. The modified material PEBA-g-AAc was characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscopy, and water contact angle. It was found that PEBA films did not suffer degradation at low doses (<30 kGy) during the grafting process. Additionally, PEBA-g-AAc was proved as drug delivery system using vancomycin as drug model. The PEBA-g-AAc with 39 and 98% of AAc loaded 63 and 98 mg g 21 , respectively. The release profiles showed a sustained delivery by 48 h with a partial retention of drug, which depends of grafting percentage. The microbiological tests showed that PEBA-g-AAc was able to inhibit the growing of Staphylococcus aureus in three consecutive challenges. V C 2017 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2018, 135, 45745.