Antibacterial treatment is an essential issue in many diverse fields, from medical device treatments (for example prostheses coating) to food preservation. However, there is a need of novel and light-weight materials with high antibacterial efficiency (preferably due to the physical activation). Utilization of photo-thermally active nanoparticles can lead to novel and re-usable materials that can be remotely activated on-demand to thermally eradicate bacteria and mitigate biofilm formation, therefore meeting the above challenge. In this study polyvinyl alcohol (PVA) hydrogel films containing non-toxic and highly photo-thermally active Prussian blue (PB) nanoparticles were fabricated. The confocal microscopy studies indicated a uniform nanoparticle distribution and a low degree of aggregation. Upon near-infrared (NIR; 700 and 800 nm) light irradiation of PVA-PB films, the local temperature increases rapidly and reaches a plateau (up to ΔT ≅ 78 °C), within ≈6-10 s under relatively low laser intensities, I ≅ 0.3 W cm-2. The high and localized increase of temperature on the fabricated films resulted in an efficient antibacterial effect on Pseudomonas aeruginosa (P. aeruginosa) bacteria. In addition, the localized photo-thermal effect was also sufficient to substantially mitigate biofilms growth.