Obtaining a better understanding of the molecular basis of cell recognition remains an important challenge with regard to the social functioning of cells in multicellular systems. The wide structural diversity of carbohydrates allows many combinatorial possibilities for fine-tuning cell-cell and cell-matrix recognition in multicellular organisms. Direct carbohydrate-carbohydrate interaction would endow both the flexibility and the specificity of reversible contacts at the cell surface during the formation, maintenance and pathogenesis of tissues. The recent development of methods for the characterization of such interactions will help to expand our knowledge of the mechanisms that trigger early events in cell recognition.