The enthalpies of dilution of aqueous solutions of acetamide, propionamide and butyramide were determined as a function of the molar fraction at 293.15 K, 298.15 K, 303.15 K and 308.15 K by flow microcalorimetric measurements. The enthalpies of dilution of amides are compared with literature data when available and the results are discussed in terms of solute-solvent interactions. The enthalpic interaction coefficients were obtained according to the McMillan-Mayer theory. The addition of a CH2 group causes an important change in the interaction coefficients. The pairwise coefficients increase as the number of CH2 groups increase. Two additivity approaches are used in this work: the Savage-Wood principle and a simple methylene additivity approach. The results obtained by both methods are presented and compared with literature data. (C) 2009 Elsevier B.V. All rights reserved.