The Schiff base complexes of Cu(II), Ni(II), Zn(II) and Co(II) have been synthesized from 4-pyridine carboxaldehyde with tryptophan. They have been characterized by UV, FT-IR techniques and their microbial and DNA cleavage activity have also been studied. The Schiff base and its metal complexes show a good activity against the bacteria; Klebsiella pneumonia, Pseudomonas aeroginosa, E.Coli, Staphylococus aureus,Proteus and fungi, Aspergillus niger. The antimicrobial results also indicate that the metal complexes of Cu(II), Ni(II), Zn(II) and Co(II) are better antimicrobial agents as compared to the Schiff bases. The DNA cleavage result reveals that all complexes showed enhanced nuclease activity.