The energies of combustion of mono- and di-ammonium succinates were measured by rotating-bomb combustion calorimetry. Enthalpies of solution of the two salts and of succinic acid were obtained by solution calorimetry. The results were used with other data to evaluate enthalpies of formation as follows: State ΔH f o(298.15 K)/kcal th mol −1 Monoammonium succinate c −255.22±0.21 Diammonium succinate c −282.67±0.18 NH 4 + aq −31.820±0.045 NH 3 aq −13.395±0.045