A series of tetra dentate macrocyclic metal complexes [M (C16H12N8) X-2] have been synthesized by template condensation of diaminomaleonitrile and diacetyl in presence of divalent metal ions where M= Co-II, Ni-II, Cu-II, Zn-II and X= Cl-1, NO3-1, CH3COO-1. Metal complexes are characterized by elemental analysis, conductance measurements, magnetic susceptibility measurements, IR, Far IR, NMR, ESR, electronic and mass spectra. Based on the molecular modeling studies and various spectral studies, distorted octahedral geometry has been proposed for metal complexes. All the complexes show low conductance values which indicate their non -electrolytic nature. Antimicrobial activities of macrocyclic complexes have been carried out in vitro against gram positive bacteria, gram negative bacteria and fungal strains showing good results as compare with standard drugs.