Copper(II) chelates of 3-nitro-1,5-diarylformazans have been synthesized by reacting aqueous solution of copper(II) acetate tetrahydrate with methanolic solution of the ligand. The so synthesized copper(II) chelates of 3-nitro-1,5-diarylformazans were purified, crystallized and characterized on the basis of elemental analysis, IR, Electronic and EPR spectral studies, and magnetic susceptibility measurements. The studies reveal that these copper(II) chelates of 3-nitro-1,5-diarylformazans characterized as bis-chelates having 1:2 stoichiometry, are paramagnetic in character and most probably have a symmetrical six membered chelate ring structure. The anti-bacterial activity of these bis(3-nitro-1,5-diarylformazanato)copper(II) chelates has been evaluated against Escherichia coli and Bacillus subtilisby disc diffusion method and compared with standard Amoxycillin and they are found to possess potent anti-bacterial activity against selected bacterial strains.