Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff bases of N'-[(E)-(2-hydroxyquinolin-3-yl)methylidene]-2-[(4- methyl-2-oxo-2H-chromen-7-yl)oxy] acetohydrazide(OHQZ) and 2-[(4-methyl-2-oxo-2H-chromen-7-yl)oxy]-N'- [(E)-(2-sulfanylquinolin-3-yl)methylidene] acetohydrazide(SHQZ) have been prepared. The titled Schiff-bases act as tridentate ligands coordinating through NOO and NSO donor sites via deprotonation during complexation. All the metal complexes are found to have the general formula ML2. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, 1H NMR, UV-visible, ESR and thermal studies. From the above studies it is found that the complexes possess octahedral geometry. The Schiff-bases and their metal complexes have been screened for their antibacterial, antifungal and DNA cleavage studies. The results reveal that the metal complexes possess higher activity than the corresponding ligands. Among the metal complexes, Cu(II) complexes are found to be more potent in antibacterial, antifungal and DNA cleavage studies.