Vapor-liquid phase equilibria in the binary system n-pentane + poly(dimethylsiloxane) (PDMS) have been investigated experimentally at temperatures ranging from 308.15 to 423.15 K. The experiments have been performed at pentane mass fractions in the liquid phase ranging, from 0 to 80% using the static method. PDMS with average molecular weights of 26 500 g/mol and 103 000 g/mol has been used. The data are in good agreement with several literature data by other researchers. mostly obtained by the use of inverse gas chromatography. The experimental data could be correlated well using the Flory-Huggins activity coefficient model for the polymer phase and the Peng-Robinson equation of state for the gas phase. Using statistical associating fluid theory (SAFT), it was only possible to reproduce the experimentally determined equilibria after adjusting the pure-component parameters of the polymer to the binary equilibria. Further, experimental data have been obtained for the R22 (difluorochloromethane) + PDMS system at 298.15 and 343.15 K.