Infectious diseases are still remains a crucial and challenging problem and metal-based drugs are found tobe morepotent than parent drugs to inhibit infection disease. In this work, Mixed ligand Cu(II) complexes containing 1,10-phenanthroline and adenide as ligands have been synthesized and characterized by different analytical and Spectroscopic techniques such as ICP-OES, UV-Vis and IR spectroscopic studies. The physicochemical data’s obtained were confirmed the successful formation of the complexes. The spectroscopic data showedthe coordination of both ligands to metal ions together with their mode of coordination and hence suggested the structural composition of the complexes. Based on the analytical, spectral and conductance data, it isfound that both complexes interpretedas square pyramidal geometry in which Cu(II) has two molecules of 1,10-phenanthroline and one molecule of water in the coordination sphere of the precursor complex and one molecule of adenide in the coordination sphere of the new metal complexesrespectively. The in vitro antibacterial activities of the complexes were tested against two gram positive (Staphylococcus aureus and Staphylococcus epidermis) and two gram negative (Escherichia coli and Klebsiella pneumonia) bacterial strains. The results of the in vitro antibacterial activities were compared with the commercially available antibiotic drugs (Erythromycin and Tetracycline).The finding of comparative study demonstrated that the newly synthesized complexes, [Cu(phen)2(Ad)]Cl and [Cu(phen)2(Ad)]ClO4 exhibited significantly higher antibacterial activity against both Gram positive and Gram negative bacteria’s strains than the commercially available antibiotic drugs. Keywords: Copper(II), adenide, 1,10-phenanthroline, metal complexes, antibacterial activit