Oligo- and polysaccharides are important macromolecules in living systems, showing their multifunctional characteristics in the construction of cell walls, energy storage, cell recognition and the immune response. The development of an efficient synthetic methodology is therefore demanded in order to supply a sufficient quantity of oligo- and polysaccharides for basic research. Although many glycosylation reactions have appeared based on the recent advances in catalysts for organic synthesis, perfect control of the regio- and stereochemistry of the glycosylating process still remains a difficult and challenging problem. Enzymes have several remarkable catalytic properties compared with other types of catalysts in terms of their selectivity, high catalytic activity, lack of undesirable side reactions and operation under mild conditions. This review presents an overview of recent advances in the synthesis of oligo- and polysaccharides catalyzed by enzymes.