A novel series of mononuclear macrocyclic metal complexes of the type [M(C28H20N4O4) X 2] using the metal (II) salts { M= Co(II), Ni (II) and Cu (II) and X= OAc- } were synthesized by the reaction of diethylphthalate with Ophenylenediamine by adopting template method. The complexes have been characterized on the basis of microanalytical, IR, UV-Vis spectral and magnetic measurement studies. Spectral studies suggested a distorted octahedral geometry around the copper ion in copper complex where as octahedral geometry around the cobalt and nickel ions in their complexes. The antimicrobial activity of the complexes have been screened in vitro against two bacteria Pseudomonas aeruginosa and Staphylococcus aureus and two fungi Rhizopus stolonifer and Penicillium notatum to access their inhibiting potential. Metal complexes exhibited enhanced antimicrobial activity in comparison to their fragments.