X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques have proved to be complementary in studying crystalline and noncrystalline systems on the short-range and mainly long-range scales, respectively. Extended X-ray absorption fine structure (EXAFS) provides details of the local structure that are inaccessible to XRD, principally owing to its Bragg scattering component, which provides information on the average of the atomic arrangements. Therefore, a complete description of the structure can be obtained by combined use of the potential of both techniques. Some examples of complementary and simultaneous data acquisition and analysis are cited in the present chapter and further developments of this synergistic approach should occur in the near future. XAS and XRD, together with continuous development of synchrotron-radiation sources, detectors and data-analysis software, have allowed a deep understanding of structure, cluster dimensions and kinetic processes to be obtained in the research fields of catalysis, amorphous solids, solutions, dis­ordered materials and macromolecular systems. Two topics which require further improvement are the time resolution and combined fast data acquisition, together with computation. In this way, joint XAS and XRD experimental methods will be able to exploit all of their potential.