Background: Moringa oleifera (MO), a medicinal, multifunctional and nutritious Asian herb, used as therapy for large number diseases including diabetes mellitus (DM). This study reports the anti-diabetic potential of MO aqueous leaf extract in the streptozotocine (STZ) induced (180mg/kg) DM in rats. Methods: 32 Sprague Dawley female rats were divided into four weight matched groups (4/group). All the groups were STZ induced, one of which was diabetic control and the remaining 3 groups were treated with 100, 200 and 300mg/kg b.w. of MO leaf extract for four weeks. The body weight and blood glucose were calculated weekly. After four weeks organs weight, total protein (TP), albumin, creatinine, alaninie amino-transferase (ALT), aspartate amino-transferase (AST), lactate dehydrogenase (LDH), high density lipoprotein (HDL), low density lipoprotein (LDL), alkaline phosphatase (ALP), triglyceride (TG) and total cholesterol (TC) in the serum and organs were calculated and compared with diabetic control. Results: The induced DM was reduced with the administration of MO leaf extract. There was a significant (P<0.05) increase in the level of TP, albumin and HDL concentration, while significant (P<0.05) decrease was observed in blood glucose, organ weight, creatinine, ALT, AST, LDH, ALP, TG, TC and LDL concentration. A non-significant (P<0.05) decrease was observed in the level of body weight of the STZ induced diabetic rats. Conclusion: The results demonstrated that MO extract (200mg/kg) caused a considerable hypoglycemic potential against diabetic rats. The results thus, showed that MO holds hepatoprotective effects and may be safer in preventing DM induced damage to the rats. Significant finding of the study: MO extract showed a potential against DM and exerted a considerable hypoglycemic activity. Further study needs to be accomplished for identification of specific components present in MO for its observed experimental effects. What this study adds: To the best of our information there has been no reported broad study to assess the anti-diabetic activity of the aqueous MO leaf extract. The present study adds the hepatoprotective effect in injury to the organs of diabetic animals.