In recent years supercritical fluid extraction has been investigated for the removal of hazardous pollutants from wastewaters, especially those contaminated with trace amounts of toxic organic compounds. A semicontinuous flow system was employed here, using supercritical CO2 and N2O, for the extraction of phenolic pollutants from dilute aqueous solutions. This study showed the extent of extraction as a function of time. The equilibrium distribution coefficients of phenol and p-chlorophenol between aqueous and supercritical fluid phases were determined at 311 and 323 K and at pressures ranging from 10.34 to 24.13 MPa.