Biologically important Schiff bases L 1 8-nitro-2-{[(5'-methyl-3'-isoxazolyl) imino] methyl } naphtha [NMIIMN], L 2 N-[5'-methyl-3'-isoxazolyl]-N-[(E)-1-(-2 Thiophene) ] methylidine] amine [MITMA] have been synthesized. Metal Chelate s of NMIIMN and MITMA with Co (II), Ni (II), Cu (II) and Zn (II) metals have been synth esized and the structures of these chelates have been elucidated by elemental analysis, 1 H _ NMR, Mass, IR electronic spectral data and magnetic moments. From these studies it is found that the li gands NMIIMN and MITMA act as bidentate ligands coordinating through oxygen and nitrogen do nor atoms in the case of NMIIMN, sulpher and nitrogen atoms in the case of MITMA. The chelat es of Co (II), Ni (II) and Zn (II) appear to be octahedral and Cu (II) appears to be tetragonal geometry. Antimicrobial activity of the ligands and their metal complexes against bacteria ( Bacillus, Pseudomonas ) and fungus ( R. Solani, A. Niger ) has been carried out. It is found that the metal complexes have higher activities than those of free ligands.