Basic properties and properties interesting for applications of transition metal nitrides are presented in this article. Starting from crystal chemistry, bonding, and preparation, the article also briefly discusses analytical chemistry of chemical and physical nitrogen analysis and standardization as well as thermodynamics. Updated portions of phase diagrams of group 4–6 transition metals with nitrogen are presented. A substantial part is devoted to the solid‐state properties because they make nitrides interesting for application. The presentation of these properties includes hardness, thermal expansion, nitrogen diffusivity, thermal properties, electrical conductivities, superconductivities, and elastic properties. Several of these properties are given as a function of temperature and composition. The topic is closely connected to article (
see
Carbides: Transition Metal Solid‐state Chemistry).