Excess enthalpies and excess heat capacities at 298.15 K for the ternary system ethanol+dimethylformamide+ tetrahydrofuran were determined by means of a flow calorimetric apparatus built in our laboratory. Experimental data were described with a Redlich-Kister type equation and compared with those of other ternary systems previously studied (ethanol+tetrahydrofuran+cyclohexane, ethanol+dimethylformamide+cyclohexane, dimethylformamide+tetrahydrofuran+cyclohexane). A peculiar behaviour was observed for mixtures containing dimethylformamide, namely the negative Values of both H-E and C-p(E) ternary contributions. A satisfactory prediction of experimental H-E data is provided by the UNIQUAC model, while UNIFAC (Dortmund, Germany) clearly fails probably owing to an unsufficient definition of interaction parameters involving dimethylformamide.