Thin water (D2O) films on MgO(100) surfaces have been studied. Water was deposited at 115 K and monolayer and multilayer films were prepared by annealing above 150 K, where the transition from amorphous solid to cubic ice is known to take place, and then re-cooling. Temperature programmed desorption traces and transmission Fourier transform infrared spectra were recorded. For the monolayer, results are consistent with an essentially flat, hydrogen-bonded water network without a significant amount of dangling OD. Ice growing on the monolayer appears to be a blend of amorphous and crystalline solid at 115 K, becoming more crystalline when annealed. (C) 2005 Published by Elsevier B.V.