Infection associated with biomaterials is a serious and widespread problem in clinical and translational medicine. Rosemary (Rosmarinus officinalis) is a medicinal herb widely used as an antimicrobial agent. The objective of this study was to investigate the antibacterial activity of rosemary extract blended with synthetic and naturally-derived polymeric biomaterials. Polyvinyl alcohol (PVA) was choosen as a synthetic polymer and chitosan was choosen as a naturally-derived polymer as they are widely used as biomaterials for tissue engineering and drug delivery. The rosemary extract was prepared by maceration extraction method, the polymer membranes were prepared by solvent casting method and the antibacterial activity was done using Gram-negative and Gram-positive strains by pour plate method. The results of this study revealed that the antibacterial activity of rosemary extract increases against both the strains (Gram ?ve and Gram +ve) when blended with synthetic polymer PVA, whereas the activity decreased when combined with PVA-chitosan. It appears that tight binding of chitosan with rosemary extract reduces the antibacterial action of chitosan. Based on this finding, it may be suggested that the rosemary extract may be used as a natural antibacterial agent to treat bactericidal infections associated with the biomaterials. © Copyright 2016 American Scientific Publishers.