Thin films of V0.50Ti0.50Ox have been deposited by RF sputtering from metallic targets. Their use as potential counterelectrodes in electrochromic devices has been investigated. It is found that although they are slightly yellow looking in transmission, the films can reversibly store relatively large amounts of charge, whilst showing a reasonably low electrochromic colouration efficiency. The electrochemistry of V0.50Ti0.50Ox is found to be simple, in fact rather similar to that of WO,, making it an almost ideal material to use in such a variable transmission device.