The present study reveals the pharmacological effect of chlorogenic acid, a major phenolic compound in plants, food, and coffee, on diabetic cataracts. Chlorogenic acid examined the inhibitory effects upon rat lens aldose reductase (AR) activity and xylose-induced rat lens opacity. The effect of chlorogenic acid on high glucose-induced cytotoxicity in lens epithelial cells was also examined. Chlorogenic acid showed potential inhibitory activity against rat lens AR, with an IC₅₀ value of 0.95 µM. The xylose-induced opacity of lenses was significantly improved after treatment with chlorogenic acid in a dose-dependent manner. Chlorogenic acid prevented high glucose-induced cytotoxicity in human lens epithelial (HLE-B3) cells in a dose-dependent manner. These results suggest that chlorogenic acid may provide a potential therapeutic approach for prevention of diabetic complications, such as cataracts.