Excess molar enthalpies of the ternary mixture : tetrahydrofuran + cyclohexane + butanenitrile and of the binary mixtures involved have been measured at 298.15 K by means of a flow microcalorimeter. The DISQUAC analysis is developed using interchange coefficients previously determined for the binary mixtures. Even neglecting ternary interactions, it is possible to obtain a satisfactory representation of the ternary system.