This paper presents the possibilities of separation of yttrium(III)-neodymium(III) and samarium(III)-neodymium(III) pairs by frontal analysis on strongly basic anion-exchangers Wofatit SBW, Wofatit SBK and Lewatit MP 5080 in the systems: 90% (v/v) 2-propanol-10% (v/v) 7 M HNO3 and 90% (v/v) 1-propanol-10% (v/v) 7 M HNO3. The best results are obtained on Lewatit MP 5080 in the 90% (v/v) 2-propanol-10% (v/v) 7 M HNO3 system. In this system, on 1 dm3 of this anion-exchanger, 1.95 kg yttrium(III) and 0.3 kg samarium(III) were purified decreasing the microcomponent content to below 10(-3)%.