Phosphorous-31 NMR: Principles and Applications focuses on the evolution of phosphorus-31 nuclear magnetic resonance (NMR) as a widely applied spectroscopic probe of the structure and dynamics of phosphorus-containing compounds. The selection first offers information on the principles and empirical observations of phosphorus-31 chemical shifts and the principles and applications of phosphorus-31 spin-spin coupling constants. Discussions focus on introduction and basic principles, directly bonded phosphorus coupling constants, and two-bond and three-bond coupling constants. The text then ponders on phosphorus-31 NMR of enzyme complexes and paramagnetic probes of enzyme complexes with phosphorus-containing compounds. The manuscript elaborates on the use of chiral thiophosphates and the stereochemistry of enzymatic phosphoryl transfer and DNA and RNA conformations. Topics include helix-coil transitions, sequence dependence of double-stranded DNA conformations, dynamic behavior of RNA and DNA, biological and genetic significance, and stereochemical problems studied with chiral thiophosphates. The conformation and dynamics of nucleic acids and phosphoproteins, relaxation behavior of nucleic acids, and theory and applications of solid-state phosphorus-31 NMR to nucleic acids are also discussed. The selection is a valuable reference for readers interested in the principles and applications of phosphorus-31 nuclear magnetic resonance.