Density data for dilute aqueous solutions of two diols (1,6-hexanediol, 2,2-dimethyl-1,3-propanediol) and two polyhydric alcohols (2,2-bis(hydroxymethyl)-1,3-propanediol, 1,2,3,4,5-pentanepentaol) are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K and at pressure close to the saturated vapour pressure of water, at pressures between 15 and 20 MPa and at p = 30 MPa. While temperature dependences of partial molar volumes of both diols are monotonous, maxima are observed on the curves for polyhydric alcohols. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. (C) 2006 Elsevier Ltd. All rights reserved.