The isothermal (vapour + liquid) equilibrium data for the 1,1,2,2-1,1,2,2-tetrafluoroethane (R134) + cis-1,3,3,3-tetrafluoropropene (R1234ze(Z)) system were determined by the static-analytical method at five temperatures from (303.150 to 343.150) K. The standard uncertainties of the temperature, pressure and composition were less than 5 mK, 0.0005 MPa, and 0.005, respectively. The experimental results were correlated by the Peng-Robison (PR) equation of state (EoS) with the Huron-Vidal (HV) mixing rule involving the non-random two-liquid (NRTL) activity coefficient model. The correlated results show good agreement with the experimental data. The average absolute relative deviations of pressure are between 0.20% and 0.35%, while the average absolute deviations of vapour phase mole fraction lay between 0.006 and 0.007. Azeotropic behaviour can be observed at four temperatures from (303.150 to 333.150) K, while zeotropic behaviour can be found at 343.150 K. (C) 2017 Elsevier Ltd.