A calculation of the energy of complete and partial misfit dislocations has been made. This suggests that the misfit between an (001) silver film and a palladium substrate will be accommodated by partial misfit dislocations. The extrinsic stacking faults associated with these partials are expected to lie in the silver film and modify its crystal structure. To test these predictions silver films were grown in ultrahigh vacuum (2 × 10-9 Torr) on cold (-5 to -105°C) palladium surfaces prepared inside the chamber. Transmission electron-diffraction patterns from these specimens showed that the silver films contained a high density of stacking faults.