Olive leaf extract (OLE) (Olea europaea L.), which has antimicrobial effect on many food pathogens, was incorporated as antimicrobial agent into polylactic acid (PLA) films. Antimicrobial activities of films were tested against Staphylococcus aureus. Increasing amount of the OLE in the film discs from 0.9 mg to 5.4 mg caused a significant increase in inhibitory zones from 9.10 mm to 16.20 mm, respectively. Moreover, incorporation of OLE and/or increasing the amount in the film formulation significantly enhanced the water vapor permeability (WVP). The water solubility and the degradation rates of films increased up to 19.3% and 22.4%, respectively. Thus, OLE incorporated PLA films have a prospectively potential in antimicrobial food packaging to reduce post-process growth of S. aureus with improved properties. (C) 2013 Elsevier Ltd. All rights reserved.