Diabetes is growing public health. The research investigated the modulatory roles of the aqueous stem-bark extract of Moringa oleifera on glucose utilization. A modified Oral Glucose Tolerance Test (OGTT) was used in studying the effect of the extract on glucose absorption, on four groups of six rats and standard methods were used to test the effect of the extract on enzyme activities (hexokinase and glucose 6 phosphatase) on three groups of six rats. In OGTT, rats in group-1(diabetic control) and group-4 (normal control) were administered with the vehicle only. The other groups were administered different concentrations of the extract in the vehicle (group-2 and 3 were 200mg/kg body weight and 300mg/kg respectively). In the enzymes activities, 200mg/kg body weight of the extract was administered to diabetic treated group whereas normal untreated and diabetic untreated received 5ml of water only. Glucose concentrations of OGTT showed increased concentration in the first 30 minutes after administration of the extract and steady time-dependent decreased concentration through 120 minutes. Group-3, showed a significant difference in each 30 minutes interval, compared to the 120 minutes (p<0.05). Each interval is significantly different from the preceded 30 minutes interval (p<0.005). Group-2 was significantly different in the first and second 30-minutes intervals, compared to the preceded interval (p<0.005). The first 30 minute interval was significantly different from the baseline and 120 minutes (p<0.05). In enzyme activities, the diabetic treated and normal untreated were significantly different from the diabetic untreated (p<0.05). The extract improved glucose utilization.