A series of organic ligands have been screened for their effectiveness as complexants for Np(IV) in a neptunium rejection stage of an advanced PUREX process. Four of these species, formohydroxamic acid, acetohydroxamic acid, glycolic acid and pyruvic acid, readily form hydrophilic complexes with Np(IV) and can strip the actinide from 30% TBP/OK (30% tributylphosphate in odourless kerosene) into nitric acid. Near infra-red spectroscopy has been used to monitor Np(IV) complexation in nitric acid. Distribution experiments have been undertaken between nitric acid and 30% TBP/OK to examine the effect of ligand and nitric acid concentration on Np(IV) stripping. Finally, it has been shown that the extractability of U(VI) is unaffected by the presence of these ligands and all can be used to selectively strip Np(IV) from a U(VI) product stream in an advanced PUREX process.