The excess molar enthalpies for (butanenitrile + benzene, or methylbenzene, or 1,2-dimethylbenzene, or 1,3-dimethylbenzene, or 1,4-dimethylbenzene, 1,3,5-trimethylbenzene, or ethylbenzene) have been determined at T = 298.15 K. The excess molar enthalpies ranged from a minimum of -57 J . mol(-1) for benzene to a maximum of 248 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 butanenitrile and each of the aromatic compounds, decreasing with increasing methyl substitution on the benzene moiety. (C) 2000 Academic Press.