The standard (p(o) = 0.1 MPa) molar energies of combustion in oxygen. at T = 298.15 K, of 5, 6- and 7-methoxy-alpha-tetralone were measured by static bomb calorimetry. The values of the standard molar enthalpies of sublimation were obtained by Calvet microcalorimetry and corrected to T = 298.15 K. Combining these results, the standard molar enthalpies of formation of the compounds, in the gas phase, at T = 298.15 K, have been calculated, 5-methoxy-alpha-tetralone-(244.8 +/- 1.9) kJ . mol(-1), 6- methoxy-alpha-tetralone -(243.0 +/- 2.8) kJ . mol(-1) and 7-methoxy-alpha-tetralone -(242.3 +/- 2.6) kJ . mol(-1). Additionally, high-level density functional theory calculations using the B3LYP hybrid exchange-correlation energy functional with extended basis sets and more accurate correlated computational techniques of the MCCM/3 suite have been performed for the compounds. The agreement between experiment and theory gives confidence to estimate the enthalpy of formation of 8-methoxy-alpha-tetralone. Similar calculations were done for the 5, 6-, 7- and 8-methoxy-beta-tetralone, for which experimental work was not done. (C) 2008 Published by Elsevier Ltd.