We report the synthesis of the Schiff base ligands, 4- [(4-bromo-phenylimino)-methyl] -benzene- 1, 2,3-triol (A,), 4-[3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,2,3-triol (AA 3-(p-tolylimino-methyl)-benzene-1,2-diol (A(3)) 3-[(4-bromo-phenylimino)-methyl]-benzene-1,2-diol (A(4)), and 4-[(3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,3-diol (A(5)), and their Cd(II) and Cu(II) metal complexes, stability constants and potentiometric studies. The structure of the ligands and their complexes was investigated using elemental analysis, FT-IR, LTV-Vis, H-1 and C-13 NMR, mass spectra, magnetic susceptibility and conductance measurements. In the complexes, all the ligands behave as bidentate ligands, the oxygen in the ortho position and azomethine nitrogen atoms of the ligands coordinate to the metal ions. The keto-enol tautomeric forms of the Schiff base ligands A(1)-A(5) have been investigated in polar and non-polar organic solvents. Antimicrobial activity of the ligands and metal complexes were tested using the disc diffusion method and the strains Bacillus megaterium and Candida tropicalis.