In oral glucose tolerance tests with methanolic extract of Nymphaea nouchali stems (MENN), the extract significantly and dose-dependently reduced blood glucose concentrations in glucose-loaded mice. At extract doses of 100, 200 and 400 mg/kg, the reductions in blood glucose levels were, respectively, 20.7, 36.9, 43.0, and 40.1%. In comparison, a standard antihyperglycemic drug, glibenclamide, when administered at a dose of 10 mg per kg, reduced blood glucose level by 45.3%. In antinociceptive activity tests with acetic acid induced pain model mice, the extract at doses of 50, 100, 200 and 400 mg/kg, significantly and dose-dependently reduced acetic acid induced abdominal constrictions in mice by 29.6, 37.0, 44.4, and 51.9% versus the 33.3 and 51.9% reductions obtained with a standard analgesic drug, aspirin, administered respectively, at doses of 200 and 400 mg per kg. The extract when administered to mice did not cause any acute toxicity when administered at doses up to 3000 mg per kg. Preliminary phytochemical analysis showed the presence of alkaloids, flavonoids, saponins and tannins in the extract, which can account for the observed antihyperglycemic and antinociceptive activities.