This paper provides vapor-liquid equilibrium (VLE) data obtained for two binary systems of pentafluoroethane (R125) + propane (R290) and difluoromethane (R32) + R290 over a temperature range from 253.15 to 323.15 K. The measurement of VLE was performed at isothermal conditions in a vapor recirculation apparatus. Both systems form azeotropes in the temperature range of this study. The experimental results were well correlated with the Peng-Robinson equation of state (PR EoS) using one parameter van der Waals one fluid model. The binary interaction parameters were optimized using the experimental data of bubble point pressure. A comparison with published experimental VLE data has been carried out by means of the PR equation of state. (C) 2003 Elsevier B.V. All rights reserved.