Excess enthalpies, H-E, at 298.15 K and atmospheric pressure are reported for binary liquid mixtures of alkanenitrile + 1-chloroalkane. These experimental results, along with literature data on excess Gibbs energies, G(E), are interpreted in terms of the DISQUAC group contribution model. The systems are characterized by three types of contact surfaces : nitrile (CN), chloro (Cl) and alkane. The interchange energy parameters of the alkane/CN and alkane/Cl contacts were determined independently from the study of n-alkane + nitrile and n-alkane + chloroalkane systems. The interaction parameters of the CN/Cl contacts are reported in this work. The quasi-chemical parameters are constant. The dispersive parameters depend on the environment of the CN and Cl groups. The model provides a fairly consistent description of the experimental data.