Blends of Ethylene-vinyl acetate and rosin EVA/Rosin with different ratios have been prepared by solution casting technique followed by exposure to different doses of gamma radiation. The blends (EVA/Rosin) were characterized by FTIR, scanning electron microscopy (SEM), X-Ray Diffraction (XRD) and mechanical properties. The blend films show noticeable miscibility between EVA and rosin at higher concentration of EVA specially 75% EVA and 25% Rosin proved by FTIR and SEM. XRD studies show that the crystallinity and phase behavior of EVA/Rosin blends varied with different ratios of the two components. Also, it was established that the mechanical properties were enriched with the addition of EVA to rosin. After that, the EVA/Rosin blends were modified through incorporation of silver nanoparticles (Ag NPs) and cinnamic acid (Cinn) with gamma radiation. Antimicrobial and antibiofilm efficiency of all films were assessed against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Candida albicans (C. albicans). The antimicrobial results had generally indicated that the all films showed a deactivation order to all the studied microbes. In a remarkable result, EVA/Rosin/ (Cinn/Ag) 5% had the most potent influence against all the examined strains. Furthermore, the synthesized compounds demonstrated improved qualitative and quantitative biofilm repression for all the tested strains. The SEM analysis of the treated cells showed noticeable morphological abnormalities (the complete lysis of the outer surface followed by deformations of cells with a rough and irregular surface). Accordingly, synthesized nanocomposites open the area of interest for environmental and biomedical applications.