The conceptually simple process of linking carbohydrate units by glycosylation has proven to be one of the most difficult synthetic processes to control from a stereochemical perspective. In particular, it is the stereocontrolled synthesis of 1,2-cis glycosyl linkages (e.g. -glucosides, beta-mannosides) which poses the most difficult challenge. The review and research presented in this book describes new ways in which stereocontrol in glycosylation reactions can be achieved. Detailed review about the various methodologies involved in achieving stereocontrolled glycosylation. Special focus has been given towards use of Neighbouring Group Participation to achieve the purpose. In my research work neighbouring group participation have been explored, utilising novel protecting groups at the 2-postion of a series of glycosyl donors. This book also discusses use of organocatalysis towards achieving stereocontrolled glycosylations. My research work involving the use of chiral Brønsted acid catalysts in stereoselective glycosylation reactions has also been explained.