Complex carbohydrates have long been known to be present at the cell-surface and inside all living cells, as part of the glycoproteins and glycolipids. These classes of macromolecules play important roles in cellular biology, namely, cellular development and differentiation, inflammation, immunity, host-pathogen interaction and cancer progression. Alterations in the expression of the enzymes, the glycosyltransferases, involved in their synthesis, result in aberrant glycosylation that is associated with many diseases. Today, the study of the biological roles of complex carbohydrates and associated proteins and lipids has been collectively called Glycobiology. The “Glycosciences in Cancer 2006,” symposium at NCI-Frederick, Frederick, MD, will gather leaders in the field to showcase their contributions and progress to date in elucidating the biological importance of cell-surface carbohydrates. The conference will highlight the role of glycans in the progression and metastatic dissemination of tumor cells. In addition, the advances in the sequence analysis, synthesis, and 3-dimensional structures of oligosaccharides, which have facilitated the accumulation of a wealth of data on the critical roles played by these highly important macromolecules, will be presented.