This chapter describes the applications of EXAFS spectroscopy for structural characterization and chemical speciation of metal complexes with small ligands in solution, and in microcrystalline or amorphous solids. A few EXAFS studies have been presented showing that the structures of chemical species in solution are not necessarily the same as in the crystalline state. Examples of solvated species include those of alkaline-earth metals, the halides, transition metals, lanthanides and actinides. Other structural or spectroscopic methods such as wide-angle X-ray scattering (WAXS) and NMR combined with EXAFS, extending the data analysis to the XANES region, as well as combination of K edge and L edges, can improve structural models. EXAFS analysis of multiple elements within the same structure, sometimes in combination with X-ray powder diffraction data, can provide 3D information, including absorber–ligand bond angles. The possibility of using EXAFS spectroscopy for analyzing a mixture of species is also discussed. Future applications will exploit very high brilliance X-ray lasers and will include monitoring reaction dynamics in real time and the rapid acquisition of high-quality high-density data sets of time-evolving systems.