The binary mixture refrigerant with (pentafluoroethane + fluoroethane), which in refrigeration nomenclature is R125 + R161, can be considered an alternative refrigerant because it is environmental friendly, has excellent thermodynamic performance, and is safe. (Vapor + liquid) equilibrium (VLE) data for (pentafluoroethane + ethyl fluoride) have been obtained at temperatures of (265.15, 275.15, 283.15, 293.15, 303.15, and 313.15) K. The experimental method used for this study is of the circulation type. Using the Peng-Robinson equation of state combined with the linear combination of the Vidal and Michelsen (LCVM) mixing rules, the modified LCVM mixing rules, and the NRTL model, the VLE data have been correlated. The results reveal that both models have good agreement with existing experimental data obtained by the apparatus. In comparison with the LCVM model, the modified LCVM mixing rule gives much better correlations for the VLE of the binary system (pentafluoroethane + fluoroethane).