Phase behavior data are presented for simvastatin, a water-insoluble drug, in supercritical solvent mixtures of chlorodifluoromethane (CHClF2) and carbon dioxide (CO2). The solubilities of the simvastatin drug in the solvent mixtures of CHClF2 and CO2 were determined by measuring the cloud point pressures using a variable-volume view cell apparatus as functions of temperature, solvent composition, and amount of the drug loaded into the solution. The cloud point pressure increased with increasing the system temperature. As the CHClF2 composition in the solvent mixture increased, the cloud point pressure at a fixed temperature decreased. Addition of CHClF2 to CO2 caused an increase of the dissolving power of the mixed solvent for the simvastatin drug due to the increase of the solvent polarity. CHClF2 acted as a solvent for simvastatin, while CO2 acted as an anti-solvent. The cloud point pressure increased as the amount of the simvastatin drug in the solvent mixture increased. Consequently, the solubility of the simvastatin drug in the solvent mixture of CHClF2 and CO2 decreased with increasing the CO2 content in the solvent mixture as well as with increasing the system temperature.