The excess molar enthalpies of (benzonitrile + benzene, or methylbenzene, or 1,2-dimethylbenzene, or 1,3-dimethylbenzene, or 1,4-dimethylbenzene, or 1,3,5-trimethylbenzene, or ethylbenzene) have been determined at T = 298.15 K. The excess molar enthalpies range from -10 J (.) mol(-1) for methylbenzene to 130 J (.) mol(-1) for 1,3,5-trimethylbenzene. The Redlich-Kister equation, the NRTL, and UNIQUAC models were used to correlate the data. The results indicate a relatively strong association between benzonitrile and each of the aromatic compounds, decreasing with increasing methyl substitution on the benzene moiety.