Amorphous Terfenol-D films were deposited on piezoelectric PMN-PT single crystal substrates in order to study the effect of an electric field-induced stress on its magnetic properties. The stress was generated by a voltage applied across the PMN-PT substrate by means of a bottom Au electrode and a Pt capping layer (top electrode) deposited on Terfenol-D. Due to the inverse piezoelectric effect of the PMN-PT substrate, the Terfenol-D film is subjected to an isotropic planar stress. For a voltage variation from 0-90 V, an increase in the coercivity from 385 Oe to 444 Oe has been observed. This may be due to an increase in the compressive stress on the film, which is explained by a model describing the stress dependence of the domain wall pinning strength. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.