The standard (p degrees = 0.1MPa) molar enthalpies of formation for liquid 1-ethylimidazole and 1-ethylpyrazole were derived from the standard molar enthalpies of combustion Delta cHm degrees in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The molar heat capacities of both liquids were measured in the temperature range (280 to 365)K by differential scanning calorimetry. The standard molar enthalpies of vaporization Delta lgHm degrees, at the temperature T = 298.15K were measured by Calvet microcalorimetry. The derived standard molar enthalpies of formation in the gaseous state are compared. [GRAPHICS]