Experimental measurements of densities and ultrasonic speeds for the binary mixtures of benzonitrile with methyl/ethyl/n-butyl methacrylates over the entire composition range were carried out in the temperature range 293.15 K-318.15 K and atmospheric pressure of 0.1 MPa. Using the experimental data, the excess molar volume, excess ultrasonic speed, excess isentropic compressibility, and excess molar isentropic compressibility have been calculated and correlated by Redlich-Kister equation. The partial molar and excess partial counterparts of molar volumes and molar compressibilities over the whole composition range; and at infinite dilution have also been calculated. The dependence of these parameters on composition and temperature has been interpreted in terms of intermolecular interactions prevailing in these mixtures. The order of interactions suggested by the excess functions is found to be MMA > EMA > BMA. The major cause of the order is the steric hindrance caused by alkyl group. The results showed the effect of varying chain length on excess functions and interactions of the system. (C) 2018 Elsevier Ltd.