Epitaxial \rmGe_2\rmSb_2\rmTe_5 thin layers were successfully grown in the metastable cubic phase on both slightly lattice‐mismatched (GaSb) and highly lattice‐mismatched (Si) templates. The higher quality of the films grown on (111)‐oriented substrates is attributed to the tendency to form layered structures in the stable bulk phase as well as to the nature of distortion in the metastable cubic phase.(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)