The high-pressure phase equilibrium of, the system carbon dioxide-methanol-water was studied by molecular simulation at temperatures near the critical temperature of carbon dioxide.-The system was modeled by multisite Lennard-Jones plus Coulomb intermolecular, potentials with common combining rules for unlike site interactions. Good agreement was observed between experimental and simulated phase equilibrium data. Reasonably accurate predictions were obtained for the two-phase liquid-liquid and three-phase liquid-liquid-vapor coexistences.