This study was carried out to investigate the blood glucose reducing effect (hypoglycemic effect) of stem bark extract of Acacia polyacantha on normal wistar rats over a 24 h period. Three groups of previously fasted wistar rats, with each group made up of 5 rats each were administered with 100, 200 and 400 mg/kg p.o of aqueous methanolic stem bark extract of A. polyacantha. The hypoglycemic effect of A . polyacantha stem bark aqueous methanolic extract was compared with that of Metformin (250 mg/kg) in fasted normal rats. Following treatment, relatively moderate to high doses of A. polyacantha (100, 200 and 400 mg/kg p.o.) produced a dose-dependent, significant reduction (p<0.05) in blood glucose levels of fasted normal rats. The three doses of the extract did not significantly alter the blood glucose levels after 2 h of extract administration. After 8 and 16 h of extract administration at a dose of 200 mg/kg significantly (p<0.05) decreased the blood glucose levels when compared to control, while the dose of 400 mg/kg significantly decreased the blood glucose levels after 4, 8 and 16 h of extract administration when compared with the control group. The Preliminary phytochemical screening revealed the presence of alkaloids, tannins, flavonoids, triterpenoids, anthraquinones, steroids and saponins. The median lethal dose (LD50) in rats was calculated to be 3807.9 mg/kg body weight. In conclusion the aqueous methanolic extract of Acacia polyacantha possesses hypoglycemic activity in normoglycemic rats.