Diethylene glycol dibenzoate (DEDB) is nowadays considered as one of the most promising environment-friendly plasticizers. Isobaric vapor liquid equilibrium (VLE) data were measured for the binary systems diethylene glycol dibenzoate (DEDB) (1) + diethylene glycol (2), DEDB (1) + octyl benzoate (2) and ternary system DEDB (1) + diethylene glycol (2) + octyl benzoate (3) at 1.0152 kPa using a modified Othmer still, which enriched the basic data for DEDB. The UNIFAC model, Wilson model, and NRTL model were used to predict the VLE data of the binary and ternary systems. The comparison reveals that on average the most accurate VLE predictions are obtained with the NRTL model.