A novel antibacterial material with surface immobilized polyvinylpyrrolidone-iodine complex was synthesized facilely by a two-step approach. First, N-vinylpyrrolidone (NVP) was photografted onto polymeric substrates, and subsequently the surface-grafted polyvinylpyrrolidone (PVP) underwent complexation of iodine. In the UV-induced photografting process, PVP was efficiently grafted onto the polypropylene (PP) film surface by a unique film interlayer photopolymerization (FIP) technique; the grafting yield (Y-g) could be controlled by varying the irradiation time or the monomer concentration. Further, we demonstrated that the grafted PVP chains could readily perform the complexation reaction with iodine as the hompolymer PVP does, which was characterized by UV-vis spectroscopy. The antibacterial activity of the modified polymer against Escherichia coli, Staphylococcus aureus, and Candida albicans was investigated. The results show that the modified PP film with surface-immobilized PVP-1 complex has a desirable antibacterial property, with broad spectrum and high efficiency. (C) 2005 Wiley Periodicals, Inc.