Abstract The extraction of Fe (III) in sulfate solution by a mixture of tertiary amine and alkylphosphonic acid monoalkyl ester or dialkylphosphinic acid as solvent was studied. The stripping of iron extracted into the organic phase with sulfuric acid was also investigated. Synergism was found to be present in the extraction of Fe (III) with these two types of solvent mixture. The extraction and stripping of iron with HEHEHP as solvent with and without the addition of tertiary amine to the organic phase were compared. It has been indicated that with the addition of tertiary amine not only are the rates of extraction and stripping increased but also the concentration of sulfuric acid required for the stripping of iron in the organic phase is reduced. Satisfactory separation was obtained with this solvent mixture for removal of Fe (III) in aluminium sulfate and zinc sulfate leaching solutions.