X‐ray diffraction under grazing‐incidence and ‐exit angles was measured on 100 keV Si+‐implanted silicon. In comparison with model calculations based on dynamical and kinematical scattering theory, depth‐resolved information on the distortions of the crystal lattice is obtained. The thickness of amorphous and damaged crystalline regions, the degree of damage and the extension of the amorphous/crystalline interfaces are determined and are found to be in good agreement with the results of transmission electron microscopy (TEM) measurements. Furthermore, recrystallization after rapid optical annealing at different temperatures has been studied and quantitative results concerning the improvement of crystal structure, the sharpening of interfaces and the decrease in the heavily distorted surface‐layer thickness a