This review focuses on chemical ligation methods for the preparation of oligopeptides and proteins. Chemical ligation is a practical and convenient methodology in peptide and protein synthesis. Longer peptides and proteins can be obtained with high yield in aqueous buffer solutions by coupling unprotected peptide segments even without activation by enzymes or further chemical agents. Several methods and protocols were developed in the past. The potential of the most important approaches of the thioester- and imine-ligation techniques is demonstrated by a broad spectrum of applications. In addition, special features and protocols such as the template-directed ligation, ligation with novel additives or solvent media, microwave-assisted ligation, and the achievements obtained with those are also highlighted herein.