Novel mixed ligand Copper, Nickel, Cobalt, Zinc and Vanadyl complexes have been synthesized from 4- aminoantipyrine and dimethyl glyoxime. The synthesi zed compounds were characterized by elemental analy sis, molar conductance, magnetic susceptility measuremen ts, IR, UV- Vis., 1 H- NMR, FAB mass and ESR spectral data. The IR spectral data of the ligands reveals that th e ligands are coordinated to the metal ion in a tet ratendate manner with N 3 O donor site. Magnetic measurements and electronic sp ectral data of the chelates suggested that all the complexes are square planar geometry except Van adyl complex which shows square pyramidal geometry. The electrolytic nature of the chelates were confirmed by molar conductance data. The redox behaviour of t he copper, nickel and vanadyl complexes in MeCN at 300 K were studied by using cyclic voltammogram. All the compl exes show their characteristic peaks at both anodic and cathodic region. The esr spectra of the copper and vanadyl complexes were recored in MeCN solution at 300 K an d 77 K and their salient features were well reporte d. The in- vitro biological screening effects of the investiga ted compounds are tested against the various bacter ia such as Escherichia coli, Salmonella typhi, Staphylococcus aureus and Pseudomonas aeruginosa.