The present work reports the values of the gaseous standard (p degrees = 0.1 MPa) molar enthalpies of formation of the three acetylpyridine isomers, at T = 298.15 K. For each isomer, that value was derived from measurements of the standard molar energy of combustion of the corresponding liquid, using a static bomb calorimeter, together with measurements of the standard molar enthalpy of vaporization, measure by Calvet microcalorimetry. [GRAPHICS] (c) 2006 Elsevier Ltd. All rights reserved.