The development of chemical glycosylation methodologies employing protection-free sugar building blocks is the holy grail of the glycochemistry. Nevertheless, the glycochemists toolbox is mostly composed of synthetic methods applicable only to the protected glycosides. Thus, environmentally friendly chemo, regio and diastereoselective reactions of free glycosides are highly needed. As the present chapter illustrates, many advances in the glycosylation reactions on unprotected glycosides were developed in the last decade. This chapter focusses on the development of chemical and biocatalyzed strategies toward methodologies using unprotected glycosides.