The bactericidal activity of TiO2 nanoparticles under visible light is very important in regards to its practical applications. In this paper, we synthesized vanadium-pentoxide-loaded TiO2 nanoparticles (V2O5-TiO2) using a chemical vapor condensation method, followed by the impregnation method, and characterized its physicochemical properties through X-ray diffraction patterning, X-ray photoelectron spectroscopy analysis, Raman spectra analysis, and Fourier transform infrared analysis. In addition, the antibacterial activity of V2O5-TiO2 nanoparticles against E. coli was evaluated and compared with pure TiO2 nanoparticles. In these experiments, the population of E. coli was shown to be significantly reduced by V2O5-TiO2 nanoparticles under illumination with fluorescent light, whereas pure TiO2 nanoparticles showed about 3.3-fold lower antibacterial activity than the V2O5-TiO2 nanoparticles. This result was most likely due to the change in surface conditions of the TiO2 nanoparticles, which was due to the loading of vanadium pentoxide on the TiO2 nanoparticles. Furthermore, both photocatalysts showed similar antibacterial activity under UV-A (352 nm) irradiation.