Isothermal vapor-liquid equilibrium at (283.15, 293.15, and 303.15) K and excess enthalpy data at (303.15 and 323.15) K have been measured for the binary reactive system water + methyl lactate. In addition, activity coefficients at infinite dilution have been determined in the temperature range of (303.15 to 333.15) K. Whereas a computer-operated static apparatus was used to obtain the isothermal P-x data, the excess enthalpies were measured by means of a commercial isothermal flow calorimeter, and the infinite dilution activity coefficient measurements were carried out using the dilutor technique. The experimental VLE, H-E, and y(i)(infinity) data were correlated simultaneously by using quadratic temperature-dependent UNIQUAC parameters.