A novel series of complexes of the type [M(TML)X2]; where TML is Tetradentate Macrocyclic Ligand; M = Co(II), Ni(II), Cu(II), Zn(II)or Cd(II); X = Cl-, CH3COO- or NO3- have been synthesized by template condensation of glyoxal and thiocarbohydrazide in the presence of divalent metal salts in methanolic medium. The complexes have been characterized by elemental analyses, conductance measurements, molecular weight determination, magnetic measurements, electronic, NMR, infrared and far infrared spectral studies. Electronic spectra along with magnetic moments suggest a six coordinate octahedral geometry for these complexes. The low molar conductance values indicates them to be non-electrolytes. The biological activities of the metal complexes have been tested in vitro against a number of pathogenic bacteria to assess their inhibitory potential.