A series of macrocyclic complexes are synthesized by condensation of acetonylacetone and carbohydrazide in the presence of divalent metal salts in methanol. The complexes are [M(TML)X2], where M = Co(II), Ni(II), Cu(II), and Zn(II); X = Cl-, [image omitted], CH3COO- and TML is a tetradentate macrocyclic ligand. The complexes have been characterized by elemental analyses, conductance measurements, magnetic measurements, NMR, infrared, and electronic spectral studies. The low value of molar conductance indicates non-electrolytes. A six-coordinate geometry with trans coordination of monodentate ligands may be proposed for all the complexes. All the metal complexes were also tested for their invitro antibacterial activities against some bacterial strains. The results obtained were compared with standard antibiotic, Ciprofloxacin. Some of the tested complexes show good antibacterial activities against some bacterial strains.