The solid solubility of propyl p-hydroxybenzoate was measured for the first time in supercritical carbon dioxide at temperatures of (308.15, 318.15 and 328.15) K and pressures from (8.0 to 23.0) MPa. The influence of cosolvents-cyclohexane, cyclohexane + acetone (molar ratio 1:1), and acetone-was studied at a mole fraction of 0.035. The data were obtained by using a flow-type phase equilibrium apparatus, which was further tested by measuring the solubility of benzoic acid in compressed CO2. The measured solubilities in supercritical CO2 without and with cosolvents were correlated using the Chrastil equation and the modified Chrastil equation, respectively.