Binary Ni(II) and Cu(II) complexes with 4-Formylpyridine N(4)-methyl thiosemicarbazone (H4FP4MT) were prepared and characterized by various spectro-analytical techniques: elemental analyses, molar conductance, magnetic susceptibility measurements, LC-MS, TGA, IR, UV-visible and ESR spectra. Elemental analyses, LC-MS and TGA studies reveal the composition as ML2 for nickel and (ML)2 for copper complexes. Interaction of the complexes with CT-DNA, investigated by electronic absorption titrations, fluorescence quenching studies and viscosity measurements suggest partial intercalation of nickel and intercalation of copper complexes with DNA. These complexes also promote hydrolytic cleavage of plasmid pBR322. Antibacterial activity of the ligand and metal complexes were studied against gram positive and gram negative bacterial strains and found to be active.