Isothermal vapour-liquid equilibrium data have been measured for the binary hydrogen sulphide-n-heptane system (H2S + n-C7) at five temperatures between 293.25 and 373.22 K, and pressures between 0.3979 and 6.8283 MPa. The experimental method used in this work is of the static-analytic type, taking advantage of two pneumatic capillary samplers (Rolsi (TM), Armines' patent) developed in the CEP/TEP laboratory. The data were obtained with uncertainties within +/- 0.015 K, +/- 0.0003 MPa or +/- 0.0006 MPa depending on the pressure transducer used, and +/- 3% for molar compositions. The isothermal P, x, y data are well represented with the Peng-Robinson equation of state using the Mathias-Copeman alpha function and the Wong-Sandier mixing rules involving the NRTL model. The experimental data are compared to predictions from the PSRK group contribution equation of state and data found in the literature. (c) 2006 Elsevier B.V. All rights reserved.