The solvent extraction of Pr(IIl),Gd(III) and Yb (III) with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one (PMBP,HP) and with mixtures of PMBP and 1-(2-pyridyl-azo)-2-naphtol(PAN,S) in-CCI⊂4⊂,C⊂6⊂H⊂6⊂ and CHCI⊂3⊂, has been studied..The composition of the extracted complexes has been determined as LnP⊂3⊂.HP and LnP⊂3⊂.S(Ln=Pr,Gd and Yb) The values of the equilibrium constants have been calculated.Weak synergistic effects were found when the metals were extracted with mixtures of the extractants