Phase equilibria in binary and ternary systems containing benzene derivatives, carbon dioxide, and water have been investigated experimentally at a temperature of 373.15 K and pressures ranging from 10 to 30 MPa. The experimental results and literature data for further systems including benzene derivatives, carbon dioxide, and water provide a basis of experimental phase equilibrium data, clearly showing the influence of the number and the position of methyl and hydroxy groups of benzene derivatives that are in phase equilibria with carbon dioxide and water. The experimental data have been correlated using the equations of state by Peng and Robinson [D.-Y. Peng, D.B. Robinson, A new two-constant equation of tate, Ind. Eng. Chem., Fundam., 15 (1976) 59-64] and Yu and Lu [J.-M. Yu, B.C.-Y. Lu, A three-parameter cubic equation of state for asymmetric mixture density calculations, Fluid Phase Equilibria, 34 (1987) 1-19] with the mixing rule proposed by Mathias et al. [P.M. Mathias, H.C. Klotz, J.M. Prausnitz, Equation-of-State mixing rules for multicomponent mixtures : The problem of invariance, Fluid Phase Equilibria, 67 (1991) 31-44]. The phase behavior of ternary systems determined experimentally, can be predicted well, using two binary interaction parameters per binary system, optimized to reproduce the phase equilibria of the binary subsystems.