Binary diffusion coefficients at infinite dilution in supercritical carbon dioxide, DAB, were measured for five n-alkylbenzenes(n-butylbenzene, n-pentylbenzene, 1-phenylhexane, 1-phenyloctane,and 1-phenyldodecane) by means of the Taylor-Aris technique in a chromatographic apparatus from 313 to 333 K and from 15.0 to 35.0 MPa. The experimental results were correlated with temperature, pressure, solvent viscosity, and solvent density. In the case of temperature dependence, additional measurements were carried out for n-pentylbenzene from 308 to 398 K at 35.0 MPa. As the five solutes are similar molecules, the corresponding states principle of Teja was tested together with the results obtained from several predictive equations based on the Stokes-Einstein formula and on the rough-hard-sphere model.