The increasing awareness of the biological importance of oligosaccharide derivatives and the growing interest in their applications to glycobiology have been major driving forces toward the development of strategies for the synthesis of the structurally closely related thiooligosaccharides and thioglycopeptides/proteins. This review covers recent work dedicated to the successful construction of various complex glycoconjugates containing thioglycosidic linkages, including target-oriented molecules. The high nucleophilicity of the thiol and thiolate groups compared with the corresponding hydroxy compounds is the basis of this success.