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 (LD_(50)) 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.