The literature dealing with the high-temperature behavior of inorganic nitrates and nitrites has been critically reviewed. Values of (GTo-H298o)/T of the reactants and products of the decomposition reactions were calculated and have been tabulated from 298 K up to as high a temperature as possible. Equilibrium constants and partial pressures were tabulated. Auxiliary data on phase transitions and densities have also been included. Qualitative information about the thermal decomposition of the salts is reviewed.