Thin films of In2O3 have been grown on Y-stabilised ZrO2(100) substrates by oxygen plasma assisted molecular beam epitaxy over a range of substrate temperatures between 650 degrees C and 900 degrees C. Growth at 650 degrees C leads to continuous but granular films and complete extinction of substrate core level structure in X-ray photoelectron spectroscopy. However with increasing substrate temperature the films break up into a series of discrete micrometer sized islands. Both the continuous and the island films have excellent epitaxial relationship with the substrate as gauged by X-ray diffraction and selected area electron diffraction and lattice imaging in high resolution transmission electron microscopy. (C) 2008 Elsevier B.V. All rights reserved.