Four metal complexes of Co(II), Pb(II),  Ni(II) and Fe(II) ions with a Schiff base derived from (3-methoxy-4-hydroxy-benzaldehyde with leucine) have been synthesized and characterized using several physical techniques, in particular; molar conductance measurements, colour, melting point,  infrared and electronic spectra. The molar conductance values reveal a non-electrolytic nature. The infrared spectral data display the coordination behaviour of the Schiff base toward Co(ll) ,pb(ll) ,Ni(ll) and Fe(ll) ions. The electronic absorption spectra of the Schiff base and its complexes show π→π* (phenyl ring) and, n→π* (HC=N) and the expected geometrical structure for the prepared complexes. The Schiff base and its complexes were tested for antimicrobial activity against gram-positive bacteria; Staphylococcus aurous; E. Coli and Klebsiella, in addition Rizopus as fungal. The effect of the Schiff base leucine complex on bacteria was recorded only against Staphylococcus aureus and Escherichia coli.