A fragment-based development of 3C-triazol-1-yl-O-galactopyranosyl aldoximes led to the discovery of highly selective and high affinity (Kd down to 11 μM) small monosaccharide based inhibitors of galectin-3. Galectin-7, 8 N-terminal CRD, and 9 N-terminal CRD bound the inhibitors only weakly. The galectin-3 selectivity was hypothesized to stem from interaction of the aldoxime moiety with a site not present in the other galectins.