In this study, isothermal vapor-liquid equilibrium (VLE) data were measured for the binary system of fluoroethane (HFC-161) + 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234yf) over the whole composition range in the temperature range from 283.15 to 323.15 K at 10 K intervals. The experimental VLE data were correlated with the Peng-Robinson equation of state. The van der Waals (vdW) one-fluid mixing rule and the Wong-Sandler (WS) mixing rule with the non-random two-liquid (NRTL) activity coefficient model were both used. The correlation results show good agreement with the experimental data. (C) 2015 Elsevier B.V. All rights reserved.