Excess molar enthalpies and excess molar volumes for (butanenitrile + acetic acid, or propanoic acid, or butanoic acid, or 2-methylpropanoic acid, or pentanoic acid, or 3-methylbutanoic acid) at T = 298.15 K are presented. The excess molar enthalpy values are found to be positive for all six systems, whereas the excess molar volumes are found to be negative. The excess molar enthalpy values are correlated by the UNIQUAC and NRTL models and also by the Redlich-Kister polynomial.