New accurate vapour liquid equilibrium data for the ternary mixture formed by dibutyl ether (DBE), toluene and heptane at 313.15K have been measured. A static method using an isothermal total pressure cell (Van Ness’ technique) has been employed. The system studied presented a slight deviation from ideal behaviour. Reduction of the experimental data has been done by Barker's method using Wohl expansion, NRTL, Wilson and UNIQUAC equations. Moreover, experimental results have been compared to predictions for the ternary system obtained from the Wilson, NRTL, UNIQUAC and UNIFAC (Dortmund) models.