2-Substituted benzothiazole is a class of heterocycles and a bicyclic ring system owing to the diverse array of biological properties, which has earned importance as a key motif in the wide range of medicinal and pharmaceutical applications. According to QSAR study, the substituent present on second carbon of the thiazole ring gives changes in the bioactivity. Benzothiazoles as ligands show very good coordination capacity with metal ions and among them have relatively high biological activity greater than those of free ligands. Benzothiazole complexes are structurally diverse as it is discussed in this book, it can form complexes with various transition metal ions. This book summarised the importance of benzothiazoles as ligands and their metal complexes. The reaction procedures, synthetic methods and physical and analytical analysis of ligands and metal complexes.