The enthalpies of formation of three A(III) nitrides, AlN, GaN, and InN with wurtzite-type structure, were assessed using an ab initio density functional theory approach. A full-potential LAPW method within the generalized gradient approximation implemented in the WIEN2k package was employed to obtain the total cohesive energies of A(III)N, the corresponding metallic elements and the N-2 molecule. Furthermore, the entropies and specific heats at T = 298.15 K were obtained from an analysis of the low temperature heat capacity data using a Debye-Einstein model. The total energies and the integrated low-temperature heat capacities were eventually combined to evaluate the resulting heats of formation of A(III)N at T = 298.15 K. (c) 2005 Elsevier B.V. All rights reserved.