Glycosylation is one of the most common posttranslational modifications, with more than half of all known proteins thought to be glycoproteins. Alterations in glycosylation play a role in a diverse set of biological phenomena including tumor cell metastasis, intracellular communication, and inflammation. The complexity of glycosylation at the molecular level and the lack of rapid analytical tools complicate the study of glycan function. We have recently developed a lectin microarray for the high-throughput analysis of glycosylation. Lectins are carbohydrate-binding proteins that have been used for decades as a detection method for glycans. By placing the lectins in a microarray format and using standard microarray printing and scanning technology, we have created a simple yet powerful technique for glycan profiling.