Isothermal vapor-liquid equilibrium ( VLE) data for ethane ( R170) + trifluoromethane ( R23) system were measured at six temperatures from ( 188.31 to 243.76) K and pressures up to 1.62 MPa. The measurements were performed with a recirculation method. The experimental data were correlated with the Soave-Redlich-Kwong equation of state using the Huron-Vidal mixing rule and the NRTL model. The calculated results agree well with the experimental data. Azeotropic VLE behaviors can be observed at certain compositions from the experimental and calculated data.