A freeze-thawing process was employed to produce both rose bengal (RB)/polyvinyl alcohol (PVA) and benzophenone (BP)/PVA hydrogels, respectively. Results indicated that only RB incorporated PVA (RB/PVA) could form hydrogel after undergoing three cycles of freeze-thawing process; One of the cycles should be conducted by freezing at -15 degrees C +/- 3 degrees C for 18 h followed by thawing at 25 degrees C for 6 h, The structural features and functional properties of the RB/PVA hydrogel were investigated by FTIR, XRD, SEM evaluations, and photo-induced antimicrobial functions were examined as well. Release of RB from the RB/PVA hydrogel,vas examined by UV-Vis spectroscopy. The freeze-thawed RB/PVA hydrogel showed antimicrobial abilities against both E. coli and S. aureus under the exposure to fluorescence light as well as UVA (365 nm) light. 0 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2418-2424, 2010