Third phase formation in the extraction of Nd(III) by 0.2 M Octyl(Phenyl)-N,N-Diisobutyl Carbamoyl methyl phosphine oxide (OΦCMPO) in n-dodecane has been studied with tri-n-butyl phosphate (TBP) and tri-n-amyl phosphate (TAP) as modifiers to provide a comparison between these two modifier systems. The effect of concentration of TAP as modifier for the extraction of Nd(III) by 0.2 M OΦCMPO has been studied. The extraction of Nd(III) by TAP/n-dodecane in the absence of OΦCMPO has also been studied and the results are reported here.