Recent results of experimental studies on magnetoelastic coupling in epitaxial monolayers are compiled and discussed in view of theoretical work. The observation of non-bulk like magnetoelastic coupling in strained systems in experiment and theory is ascribed to an effective and strain-dependent magnetoelastic coupling. It is described as a second-order strain contribution to the energy density. We comment on the importance of inhomogeneous strain and of its relaxation for the magnetic anisotropy of nanostructures.