Liquid-liquid extraction of tungsten and molybdenum by Alamine 336, and the selective extraction of molybdenum in the presence of tungsten by DEHPA, from aqueous solutions, was studied in a rotating disc contactor (RDC) of 72 mm diameter and 1.1 m effective height. It was found that the extraction efficiency for tungsten, molybdenum, and molybdenum in the presence of tungsten increases as rotor speed and organic phase/aqueous phase flow rate ratio increase. The selectivity for the extraction of molybdenum in the presence of tungsten obtained with the RDC is higher than the corresponding equilibrium values.