This work presents mass transfer modeling of solvent extraction by means of membrane contactors. Model was based on solving conservation equations for solutes in the membrane contactor. The system considered here was a polymeric membrane contactor, an aqueous solution of ethanol or acetone, and a dense solvent. The equations of the model were solved by numerical method using CFD techniques. The simulation results for ethanol and acetone showed an average deviation of 15.6% and 2.5% with the experimental data, respectively. Simulation results indicated that the extraction of acetone is higher than ethanol due to higher solubility of acetone in the solvent. The simulation results revealed that decreasing feed velocity and increasing solvent velocity increase solute removal. The developed mass transfer model is more accurate than other models and represents a general approach for simulation of membrane-based solvent extraction. (C) 2011 Elsevier B.V. All rights reserved.