The homo binuclear complexes of Cr III , Mn II , Co II and Ni II metal ions with a binucleating tetradentate Schiff's base ligand 1,4-diformylpiperazinebis(carbohydrazone) have been synthesized and characterized on the basis of elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, UV, EPR spectral studies and thermal studies. The general stoichiometries of the complexes are found to be [Cr 2 (H 2 L)X 4 ], [Ni 2 (H 2 L)X 2 ] and [M 2 (H 2 L)X 2 (H 2 O) 4 ], where M = Mn II and Co II , H 2 L = dideprotonated ligand, and X = NO 3 - and OAc - . The studies reveal that the complexes possess the binuclear monomeric compositions and octahedral geometry for Cr III and Mn II complexes, whereas the Co II and Ni II complexes have tetragonal and square planar geometries, respectively.