There are two contemporary conflicting, indeed, incompatible determinations of measurements of the enthalpies of combustion and of formation of pyrazine-2-carboxylic acid in the literature, (-2268.0 +/- 0.9 and -271.2 +/- 1.1 kJ . mol (1)) and (-2211.4 +/- 0.9 and -327.8 +/- 1.1 kJ . mol (1)). The current paper discusses these two sets of values and from the use of a measurement of the enthalpy of sublimation, a newly evaluated enthalpy of formation of pyrazine itself, and of the quantum chemical calculations at the G3(MP2)//B3LYP level, the former results are accepted and the derived gas phase enthalpy of formation, -(167.6 +/- 3.1) kJ . mol (1), suggested. (C) 2016 Elsevier Ltd. All rights reserved.