Experimental results for the high-pressure (vapor + liquid) equilibrium of binary systems of carbon dioxide + (either water or acetic acid) are reported for temperatures from 313 to 353 K and pressures between 1 and 14 MPa. The experimental results are correlated using the modification of Melhem et al. [G.A. Melhem, R. Saini, B.M. Goodwin, A modified Peng-Robinson equation of state, Fluid Phase Equilibr. 47(1989) 189] for the Peng-Robinson equation of state and the mixing rule of Panagiotopoulos and Reid [A.Z. Panagiotopoulos, R.C. Reid, Equations of state: theories and applications, in: K.C. Chao, R.L. Robinson (Eds.), ACS Symposium Series, vol. 300, American Chemical Society, Washington, DC 1986 pp. 571]. The correlation of the experimental data for (carbon dioxide + water) required temperature-dependent binary interaction parameters. Correlating the data for (carbon dioxide + acetic acid) was not very successful as long as the dimerization of acetic acid was neglected. However, including dimerization resulted in a reliable correlation and even a successful prediction of the high-pressure (vapor + liquid) equilibrium from pure component data alone. (C) 2000 Elsevier Science B.V. All rights reserved.