One N,O-bidentate dimedone derivatives ligand (1) and its Ni(II), Pd(II), and Cu(II) complexes (2,3,4) have been prepared and structurally characterized by the spectroscopic methods such as FT-IR, NMR, and X-Ray. 1,3, and 4 crystallize in the triclinic crystal system in the space group P-1, 2 crystallizes in the monoclinic crystal system in the space group C2/c. X-Ray diffraction studies showed 1 exists in enamine form, 2-4 have a square planar geometry around metal atoms which are surrounded by two nitrogen and two oxygen atoms from two ligands. Antibacterial properties of 1-4 have been examined against selected bacteria and yeast strains. Also, the minimum inhibitory concentration of 1-4 against these pathogens was compared with the selected antibiotic drugs. The result revealed that all compounds have good activity.