Ultraviolet photoemission has been used to study the growth of ultrathin films of In 2 O 3 on NiIn(0001), a model material for technologically important indium-tin-oxide (ITO). He II excited In4d spectra are shown to be an excellent monitor of the indium oxidation, which allows an interface layer to be discerned between the alloy and In 2 O 3 film. The growth of the second layer begins before the completion of this layer. Valence band spectra show that the electronic structure of the films is consistent with photoemission data from bulk In 2 O 3 and In 2 O 3 grown on Si(111), and with published density of states calculations. From a comparison of He I and He II excited valence band spectra we suggest that the valence band contains a finite contribution from In4d antibonding states, as seen in the published calculations. With the exception of oxygen plasma treated ITO, which also shows significant differences to the calculations, the In 2 O 3 /NiIn(0001) valence band spectra are in good agreement with spectra from differently treated ITO samples.