The present paper deals with surface superhydrophilic properties of mesoporous silica thin films containing tungsten oxide species (W-MSTFs) prepared by a sol-gel/spin coating method. The local structure around tungsten oxide species as well as photoinduced surface properties have been investigated by XRD, UV-vis, and water contact angle (CA) measurements. These investigations showed that tungsten oxide species are tetrahedrally-coordinated and exist in isolated states. The water CA measurements also demonstrated that W-MSTFs exhibited the high surface hydrophilic property without the UV-light irradiation. It was also found that the UV-light irradiation led to the decrease in the CA of W-MSTFs, indicating that W-MSTFs showed photoinduced superhydrophilicity. Furthermore, very low CA below 10° was maintained for about three months in the dark conditions after the UV-light irradiation. [DOI: 10.1380/ejssnt.2009.141]