Thermal initiation of the reaction of lithium nitride with anhydrous transition-metal halides produces crystalline transition-metal nitrides of various compositions MxNy(M = Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr or Mn)via an exothermic solid-state metathesis reaction. Reaction of anhydrous late transition-metal halides with lithium nitride produces the metal (M = Mo, W, Fe, Co, Ni, Cu, Pt, Zn or Cd), dinitrogen and lithium halide. The metal nitrides were purified by tetrahydrofuran trituration and characterised by X-ray powder diffraction, scanning electron microscopy, energy dispersive analysis with X-rays, magnetic moment measurements, FTIR spectroscopy and microanalysis.