Solvent extraction separation of light group rare-earth elements in a quaternary ammonium compound-chelating agent system was demonstrated in single-stage studies. Typical separation factor values obtained were 93 for lanthanum-praseodymium, 5.4 For praseodymium-neodymium, and 11.6 For neodymium-samarium. These values are significantly higher than those obtained using organophosphate extractants. Further studies in a 20-stage countercurrent mixer-settler resulted in the production of 99 percent lanthanum (oxide basis) of 96-percent recovery. Subsequently, 88 percent of the neodymium with a purity of 92 percent was recovered in the raffinate.