Densities for binary mixtures of acetonitrile with dichloromethane, trichloromethane and tetrachloromethane have been measured at 298.15 K and atmospheric pressure using a vibrating-tube densimeter. Excess molar volumes (V-m(E)) were determined. The systems exhibit negative V-m(E) values over the entire composition range at the temperature studied. The experimental V-m(E) results studied here have been used to test the extended real associated solution 11 (ERAS)-Model.