Glycation of proteins starts with the formation of Schiff base, followed by intermolecular rearrangement and conversion into Amadori products. When large amounts of Amadori products are formed, they undergo cross linkage to form a heterogeneous group of protein-bound moieties, termed as Advanced Glycation End products (AGEs). The formation of AGEs is irreversible process, causing structural and functional changes in protein. This results in generation of free radicals which play an important role in pathophysiology of ageing and diabetes. The rates of these reactions are quite slow and proteins with large amounts of lysine residues undergo glycation with significant amounts of AGEs. The unwanted consequences of protein glycation may lead to several metabolic disorders like diabetes, arteriosclerosis, osteoporosis and Alzheimer's disease etc. and their complications. This commentary reviews the glycation of proteins which have already been demonstrated by us and others.