Abstract: The present invention provides a method for preparing mesoporous TiO2 thin films with high antibacterial and photocatalytic activities. The method involves coating onto a substrate a TiO2 sol-gel prepared from hydrolysis and condensation of titanium alkoxide in the presence of a stabilizer and thermally treating the substrate at a temperature ranging from 400° C. to 900° C. The TiO2 thin films fabricated according to the method of the present invention show two times higher antibacterial and photocatalytic activities than the conventional TiO2 thin films.