Photoelectron diffraction and Auger-electron diffraction studies to date have involved the study of the elastically scattered or ``no-loss'' features in spectra. In this work, we consider the diffraction patterns associated with inelastically scattered electrons in plasmon satellites. Although very similar in most peak positions, the elastic and inelastic photoelectron patterns are found to be significantly different in intensity for emission along low-index directions in both W and Ge crystals. These differences are explained for the model case of Al in terms of defocusing due to multiple-scattering effects.