[en] A review of the literature dealing with the extraction of lanthanides and yttrium with di 2-ethylhexyl phosphoric acid is presented. The effect of various factors on the distribution coefficient is discussed. The distribution coefficient increases with the increase in the atomic number of a lanthanide. In this series yttrium is placed between holmium and erbium. An increase in acid concentration in the aqueous phase reduces the distribution coefficient; for diluted solutions it is inversely proportional to the cube of acid concentration, for concentrated solutions no such relation is found. The type of solvent used affects considerably the distribution coefficient. In the hydrocarbon systems the distribution coefficients are much higher than those in alcoholic systems. The mechanism of the extraction process is complicated and depends on acid concentration in the aqueous phase. To simplify the matter, one may assume that at low acid concentrations three dimerized extraction solvent molecules split off one hydrogen ion and attach one lanthanide ion. At high acid concentrations the above mechanism is replaced by the solvation mechanism. The distribution coefficients of lanthanides at other oxidation states are very different from those at oxidation state (3); the distribution coefficient of cerium (4) is about 1000 times greater than that of cerium (3) whereas the distribution coefficient europium (2) is at least 1000 times smaller than that of europium (3). This provides for relatively easy separation of cerium and europium from a mixture of lanthanides by the fractional extraction method. (author)