Isothermal vapor liquid equilibrium (VLE) data were measured for binary mixtures of 2-pentanone + 2-methylpropan-1-ol at (343.15, 358.15, and 363.15) K. A glass dynamic recirculating still suitable for a subatmospheric to atmospheric pressure range was used for the VLE measurements. The excess thermodynamic properties, namely, the molar excess Gibbs energy (G(E)), heat of mixing (H-E), and molar excess entropy (S-E) were derived from the measured isothermal VLE data. The calculated infinite dilution activity coefficients for the system are also presented. The measured isothermal VLE data for the binary system was regressed using the gamma phi (gamma-Phi) approach. The Wilson and the nonrandom two-liquid (NRTL) activity coefficient models were employed for the data regression, while the Hayden and O'Connell correlation was used to account for the nonidealities in the vapor phase. Satisfactory results were obtained using the Wilson and NRTL models to represent the measured data. The measured VLE data were considered to be thermodynamically consistent following the point test of Van Ness et al. (Van Ness, H. C.; Byer, S. M.; Gibbs, R. E. AlChE J. 1973, 19, 238-244) and the more rigorous direct test (Van Ness, H. C. Pure Appl. Chem. 1995, 67, 859-872).