Experimental densities of hexane and hexane + benzothiophene mixtures were obtained via a vibrating tube densimeter. Densities of hexane were measured from (313 to 363) K and pressures up to 25 MPa. For the case of hexane (1) + benzothiophene (2) mixtures, the experiments were performed at five compositions (x(1) = 0.0629, 0.2588, 0.4495, 0.7491, and 0.9432) in the same range of temperatures at pressures up to 20 MPa. Uncertainties for measured densities were estimated within 0.2 kg center dot m(-3). The obtained densities of hexane were compared with those values reported in the literature and with the results obtained by the Tait equation and the equation of state proposed by R. Span and W. Wagner (Int. J. Thermophys. 2003, 24, 1-39). These were also correlated with a modified five-parameter Toscani-Szwarc equation (MTS). Good agreement was found in all cases. Excess molar volumes for the mixtures, as well as isothermal compressibilities and isobaric thermal expansivities of hexane, were calculated using the reported parameters for the MTS equation.