Finally, for the applications of WOx, we have detailed the traditionally popular areas such as electrochromic devices, photocatalysis, and sensing devices. The studies in these areas are relatively advanced. However, there is still significant room for improvement of the capabilities of these devices through exploitation of nanostructured WOx. In addition, we have reviewed some pioneering studies of WOx, which are used in dye-sensitized solar cells, optical data storage, field-emission displays, of high-Tc superconductors. Although WOx may not be the optimal material for each of these applications, it can provide an effective alternative in circumstances where the optimal material is simply not practical. Furthermore, since WOx can be well dispersed in liquid in a variety of nanostructured forms, one should consider the opportunity for its use in drug delivery and sensors in microfluidic systems.