A phenol based novel Schiff base polydentate symmetric ligand was prepared. The complexes were prepared by reacting ligand and the metal chlorides of Cu (II), Ni(II), Co(II) and Fe(II) in methanol to get a series of mononuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, NMR and API-ES mass spectral data. The mononuclear structure of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility and API-ES mass spectral data. The ligand and all the metal complexes were evaluated for their antimicrobial activity against four Gram-positive bacteria (Staphylococcus aureus ATCC 6538, S. aureus ATCC 25923, Bacillus cereus ATCC 7064 and Micrococcus luteus ATCC 9345), one Gram-negative bacterium (Escherichia coli ATCC 4230), and three yeast (Candida albicans ATCC 14053, Candida krusei ATCC 6258 and Candida parapsilosis ATCC 22019) strains. Therefore, newly synthesized the ligand and two complexes [(Cu(II) and Co(II)] showed good biological activity against all tested bacteria and yeast strains. (C) 2010 Elsevier Masson SAS. All rights reserved.