The kinetics of europium extraction into D2EHPA is studied in a stirred cell. For the range of concentrations investigated (10−6kmol/m−3≤ [Eu3+] ≤ 10−4kmol/m3; 0.01 kmol/m3≤ [H+] ≤ 0.15 kmol/m3; 0.001 kmol/m3≤ [(HX)2] ≤ 0.05 kmol/m3) extraction rate increases linearly with stirring speed, i.e. mass transfer is limited by diffusion. An increase in proton concentration or a decrease of complexant concentration reduces fluxes but does not change the extraction regime. Based on the found equilibrium constant and individual mass transfer coefficients, extraction rates are calculated showing good agreement with experimental data. The influence of concentrations on extraction rate is explained by the gradient between bulk concentration and interfacial concentration as the driving force for mass transfer in an extraction system controlled by diffusion.