Mixed-ligand metal complexes of Ni(II) and Zn(II) with Diphenylacetic acid and heterocyclic amines bases have been synthesized. The complexes of the following compositions were prepared [M(RCOO)(L)(H2O)]2Cl2, where, M=Ni(II) and Zn(II)R=(C6H5)2CH, L=Quinoline, 2-picoline, pyridine, isoquinoline, 2-aminopyridine, α-pic=α-picoline, Py=Pyridine. Synthesized complexes were characterized on the basis of elemental (metal) analysis, conductivity measurements, magnetic measurements, infrared and UV spectral studies. The IR spectral data indicated that the ligand coordinated to the metal through O and N atoms. Magnetic moments are in good agreement with the square planner geometry of metal complexes. The present results revealed that the complexes are more microbial toxic than the free metal ions or ligands. The complexes showed strong to mode-rate activity against both Gram positive and Gram negative bacteria compared to standard Kanamycin indicating the higher zone of inhibition.