Abstract: Since the coordination number of lanthanides is usually 8 or more, it is quite difficult to prepare the hexa-coordinated rare earth complexes of pyrazolone of composition REA₃·Recently Roy and Okafor reported the synthesis of 8 rare earth complexes of the title ligand and it was said which had the composition of REA₃·We have repeated their experiments many times, but the products obtained and very carefully characterized always remained REA₃·HA. In the present investigation, we have synthe-sized 15 REA₃·CeA₄ and 15 REA₃·2H₃O complexes by a new procedure, and also 14 REA₃·HA complexes. The composition of these 45 complexes was carefully characterized by elemental analysis, Fourier transform infrared spectra in the far and middle infrared range and NMR studies. Among these 45 compounds, 30 have not been reported previously.