Mammalian cell surfaces carry sugars of various types that enable cell-to-cell communication through their interaction or binding with a large and diverse group of proteins called lectins. Cell-surface carbohydrates have many far-reaching biological effects. Certain types of cancer, fetal development, and bacterial and viral infections all involve interaction between a lectin and a cell-surface carbohydrate molecule as part of the progression of biochemical events. Thus, the control of carbohydrate-mediated physiological processes is currently an active area of drug design. In many lectins and some glycosidases, glucose/mannose recognition is accomplished though a common set of binding contacts. We used these binding contacts to construct a glucose/mannose pharmacophore, and searched commercial chemical databases for molecules that contain the pharmacophore. These molecules were docked in the active site of the lectin Concanavalin A, and the most promising compounds were purchased and tested for inhibition of mannose binding to Concanavalin A. Current results, including the most potent inhibitors and insights into carbohydrate-based drug design, will be discussed.