AbstractGalectins are a family of proteins defined by their affinity for β‐galactoside and by their conserved sequence. Each galectins exhibits a specific expression pattern in various tissues and their expression is regulated during development. Their expression is altered in many types of cancers and non‐cancerous disorders. They interact with glycoproteins in both extracellular and intracellular milieu and regulate various biological phenomenon including cell growth, cell differentiation, cell adhesion, and apoptosis. A series of experimental and clinical evidences have been reported to support correlation between galectin expressions and neoplastic transformation. The recent findings show that expressions of galectins are elevated with neoplastic progression in certain malignancies, and therefore, galectins are expected to serve as reliable tumor markers. In this review, we describe the expression and role of galectins in urological cancers and their clinical applications for diagnostic and therapeutic use. © 2003 Wiley‐Liss, Inc.