This study was to determine the effects of aqueous root extract of Moringa oleifera on antioxidant activities and on the histology of pancreas in Alloxan-induced-diabetic rats. Twenty Albino Wistar rats of both sexes weighing between100 and 194g were used for the study. The animals were divided in to four groups (Groups I, II, II and IV) of five rats each. Group I was the control group and were administered distilled water per body weight. Group II was induced with diabetes by injecting the rats with 150mg/kg Alloxan single dose and not treated. group III was induced with diabetes and treated with 50mg/kg Moringa for 28 days and group IV were not induced with diabetes but were treated with the aqueous extract of Moringa oleifera root for a period of twenty-eight days at 50mg/kg orally. The antioxidant activity of Moringa oliefera aqueous root extract was studied by assaying serum marker substances of Catalase, Glutathione peroxidase (GPx), Superoxide Dismutase (SOD) and Malondialdehyde (MDA) to determine the extent of antioxidant activity of the extract on the pancreas. At the end of the experiment, the animals were sacrificed and the Pancreas processed for routing light microscopic analyses. The results of this study showed that antioxidant activities of Malondialdehyde (MDA) decreased significantly in diabetic not treated and diabetic treated Moringa groups and Glutathione peroxidase (GPx), activity increased significantly in diabetic non-treated group and non-diabetic treated group (p<0.05). Glutathione Superoxide Dismutase (SOD) and Catalase changes were not significant. The results of this study also showed that photomicrograph of pancreas of diabetic non treated rats showed highly lobulated pancreatic tissue, glands exhibits loose collagenous capsule which can be seen extending as delicate septae, chronic inflammation and degeneration of islets of Langerhans. Diabetic treated group also showed septea between the lobule similar to the control group and glandular acini undergoing regeneration. Non-diabetic but treated group showed diffused micro and macro acini and normal islets of Langerhans similar to control.