Isothermal vapour+liquid equilibria data were measured for the binary systems pentafluoroethane+cyclopropane and cyclopropane+ 1,1,1,2-tetrafluoroethane at 253.15, 273.15 and 293 15 K, using a static analytical method. The phase compositions at equilibrium were measured by gas chromatography. The experimental estimated accuracies are +/- 0.02 K for temperature, +/- 1kPa for pressure, and 0.003 in mole fraction for both liquid and vapour phase composition. Both systems show strong positive deviations from Raoult's law with the formation of an azeotrope. The experimental data were regressed using the Peng-Robinson-Stryjek-Vera equation of state, with different mixing rules, i.e. the Van der Waals mixing rule with one or two interaction parameters, and Huron-Vidal and Wong-Sandier mixing rules. A comparison with literature data was performed. (c) 2006 Elsevier B.V. All rights reserved.