This paper presents measurements of the enthalpy of vaporization of pure and binary hydrocarbon fluid mixtures using a commercial differential scanning calorimeter (DSC). The DSC was modified to allow the direct measurement of enthalpies of vaporization, Delta H-vap, at temperatures as low as 80 K and pressures as high as 10 MPa and was tested by measuring enthalpies of vaporization, both under vaporization and under condensation, for pure methane at T = (118, 123, 128, and 133) K and pure ethane at T = (208 and 213) K. The measured values had relative deviations of less than 3% from recommended literature values. Then Delta H-vap was measured for mixtures of methane + ethane, methane + propane, and ethane + propane at various temperatures by both condensing and vaporizing samples. In contrast to the pure fluid measurements, the measurement pathway affected the value of Delta H-vap obtained because the condensation occurred along a constant composition pathway whereas the composition varied during vaporization as a result To facilitate comparison of the Delta H-vap measured for mixtures along the vaporization pathway, samples of the vapor phase produced at different temperatures were captured and their composition analyzed. For the mixture with a cricondentherm temperature below 235 K, the Delta H-vap values measured during both condensation and vaporization had relative deviations from the values predicted using the GERG EOS of less than 2%. However, for the other mixtures with higher temperature cricondentherms relative deviations between 5% and 40% were observed because of limitations with the fill stem's temperature control. This analysis of the limitations of the mixture measurements could enable more successful efforts in the future.