Densities, refractive indices, speeds of sound, and isentropic compressibility at 298.15 K and isobaric vapor-liquid equilibria data at 101.3 kPa were reported for the binary mixtures ethyl acetate + ethyl lactate and methyl acetate + ethyl lactate. Excess molar volumes, refractive index deviations, changes of speed of sound, and changes of isentropic compressibility on mixing were calculated from the measurement results that were fitted with Redlich-Kister polynomials. VLE experimental data were tested for thermodynamic consistency by means of Dechema test and were demonstrated to be consistent. The activity coefficients were correlated with the Margules, van Laar, UNIQUAC, NRTL, and Wilson equations. The ASOG model also was used for prediction.