In this paper, cobalt (Co)-organic composite thin films were fabricated from an organometallic precursor by plasma-enhanced chemical vapor deposition (PECVD) under various conditions. The amount of Co in the thin film was controlled by adjusting the operating parameters of the PECVD, including the vaporizer temperature, plasma deposition time, and organometallic precursor flow rate. The antibacterial performance of the Co-organic composite thin films with various amounts of Co was tested by a 'film attachment' method using Staphylococcus aureus and Escherichia coli. It was observed that the antibacterial performance was enhanced by increasing the amount of Co in the Co-organic composite thin film, and the critical amount of Co for preventing the growth of bacteria was found to be similar to 1.6 ppm/cm(2). (C) 2008 Elsevier B.V. All rights reserved.