The densities of coenzyme Q(10) in supercritical carbon dioxide were measured at 308.15, 313.15, 323.15 and 333.15 K and in the pressure range from 10 to 40 MPa with the vibrating tube densimeter. The reliability of the technique has been verified in our previous works and in the present work it was checked comparing our experimental densities of pure carbon dioxide with literature data. The partial molar volumes, isothermal compressibilities, isobaric thermal expansivities, internal pressures and cluster sizes were calculated from obtained densities. (C) 2006 Elsevier B.V. All rights reserved.