Momordica charantia (L.) [Cucurbitaceae], more commonly known as the bitter cucumber or bitter melon, is a plant used for food and medicine. In the Ayurvedic tradition it is used to treat a range of disorders, including diabetes. This study has demonstrated the plant's anti-hyperglycaemic effect in mice with alloxan monohydrate induced diabetes. Two extracts were prepared, from both the fresh and the dried fruit of the plant, and their effects on blood sugar levels were compared with the reference anti-diabetes molecule glibenclamide. Aqueous extract of the fresh fruit at a dose of 200 mg/kg demonstrated a significant reduction in glycemia (62%), comparable with that of glibenclamide at a dose of 10 mg/kg. The two extracts at different doses showed no signs of toxicity. Thus, aqueous extract of the edible plant M. charantia would appear to be a viable alternative for reducing glycemia as well as providing an auxiliary and complementary treatment which would limit the secondary effects of allopathic remedies using synthetic drugs.