A series of chemical and biological investigations has proved that Schiff bases are very important ligands and take part in many non enzymatic processes. The Schiff bases have identified as best chelating ligands and form stable metal complexes with transition metals, therefore, these are widely used ligands in the synthesis of transition metal complexes. Although, these metals occur in trace amount but form stable complexes with Schiff bases ligands having wide range of applications in living organisms. This book, therefore, gives a deep insight into the transition metal complexes of Schiff bases and their biological applications including antibacterial, antiviral, antifungal, etc.