Different mass transfer models were evaluated on the basis of zinc extraction with the liquid ion exchanger di(2-ethylhexyl)phosphoric acid. Comparison of the models showed that the film model inadequately describes the time dependence of zinc concentration in aqueous solution. The best match of the measured time-concentration profiles was achieved by adapting the film-penetration model. Studies were carried out in a stirred cell with a planar interface stabilized by the mixing conditions. Under the chosen experimental conditions mass transfer was limited by zinc transfer in the aqueous phase. The mass transfer equations of each model were solved analytically using empirical correlations for the modeling parameters.