Isobaric vapor-liquid equilibrium data for the binary system maleic anhydride+dimethyl phthalate at 2.67, 5.33 and 8.00 kPa were determined using the ebulliometric method. Saturated vapor pressures of pure dimethyl phthalate were also measured and Antoine constants were obtained. The experimental equilibrium temperatures, pressures and feed compositions were used to obtain NRTL parameters and equilibrium liquid and vapor compositions. Moreover, vapor-liquid equilibrium data for the binary system were predicted by use of the UNIFAC model. Predicted results were compared with those from the ebulliometric method, and good agreement was found. (c) 2006 Elsevier B.V. All rights reserved.