Chiral derivatizing agents enable effective enantiodiscrimination in NMR spectroscopy by forming covalent diastereomeric derivatives that produce measurable chemical shift differences. Their successful use requires high enantiomeric purity, reactive functionality, mild and stereochemically stable reaction conditions, and avoidance of kinetic resolution. Beyond determining enantiomeric composition, CDAs assist in assigning absolute configuration through predictable anisotropic NMR effects. Structurally, they typically include a linker group, an anisotropic moiety, a conformational inductor, and supporting functional elements, collectively governing the extent of NMR differentiation. This chapter outlines the structural principles, mechanisms, and analytical applications of CDAs in NMR-based stereochemical analysis.