The applicability of the ERAS-Model to strong polar systems such as 1-alkanol + acetonitrile was analysed. For this purpose, densities for binary mixtures of 1-heptanol and l-octanol with acetonitrile have been measured at 293.15, 298.15, and 313.15 K using a vibrating-tube densimeter. Excess molar volumes (V-m(E)) were determined. Both systems exhibit positive V-m(E) values over the entire composition range in the temperature range studied. ERAS-Model calculations allowing for self-association for both components alkanol and acetonitrile were performed. The agreement between theoretical and experimental results is satisfactory only for the composition central range. A simplified version of the model, without the chemical contribution, gives better results. (C) 1998 Elsevier Science B.V.14341671143152