The temperature evolution of the microstructure in a series of  fiber textured Ag/Ni multilayer samples has been studied by in situ X-ray diffraction. From the recorded pattern analysis, two regimes can be distinguished. At low temperature (TGB = 120–130°C) where diffusion is likely insignificant, the observed reduction of the width and the increase of the intensity (sharp and quick in some cases) of 111 line-profiles indicate that microstress and defects densities possibly located in column/grain boundaries are considerably lowered. At higher temperatures, diffusion of Ag leads to a transformation of the multilayer stacking essentially characterized by the formation of long Ag coherent domains with (111) planes parallel to the film surface accompanied with a similar but minor effect on Ni. In Ag, some 002 texture component also appears upon annealing. A simple model is proposed to describe the metal recrystallization competing with areas where the multilayer stacking is kept nearly unchanged.