Some novel series of 5-chloro isatin and 4-aminoantipyrine based Schiff bases with transition metal(II) complexes of (Cu, Co, Ni and Zn) have been prepared and characterized by physical, analytical and spectral data. The synthesized ligand behaves as a neutral tridentate is confirmed by spectral techniques. During the complexation, the stoichiometry ratio 1:2 (metal:ligand) is followed and an octahedral arrangement is adopted by all the metal complexes. The calf-thymus DNA interacts with complexes via an intercalative mode is studied by electronic absorption titration. Moreover, all these synthesized metal(II) complexes were tested against a set of bacterial and fungal strains reveals that complexes exhibit better activity than free ligand.