Diabetes mellitus (DM) is a heterogeneous complex metabolic disorder resulting from defective insulinrnsecretion, resistance to insulin action or both. Broadly it is classified into two categories type-1, and type-2. Itrnis a chronic disease characterized largely by disordered metabolism, glucose urea, negative nitrogen balance,rnand hyperglycemia. In the long term hyperglycemia has pathologic effects such as atherosclerosis,rnneuropathy, nephropathy, and others which largely are due to oxidative stress. Since the currently availablernoral hypoglycemic drugs and insulin have limitations the search for better treatments is going on. Despite therndevelopments of modern treatments the interests in the plant remedies have been renewed. In similarrnfashion to other countries, in the indigenous system of Ethiopian traditional medicine different plants arernused to treat various diseases, such as diabetes mellitus, hypertension, malaria and gastrointestinal disordersrnof various origins of which Moringa stenopetala, Melia azedarach and Taverniera abyssinica are the mostrncommon. The present study was carried out to investigate the hypoglycemic and antidiabetic effects andrnantioxidant activities of the methanolic crude root extracts of Taverniera abyssinica in STZ induced diabeticrnrats. The effects of the plants’ crude root extracts on blood sugar, the level of plasma MDA, plasma totalrnperoxides, plasma total antioxidant capacity was measured and the level of oxidative stress index wasrndetermined.rn rnResults of intraperitoneal glucose tolerance test showed that crude root extracts of Tavererneira abbysinicarnhave hypoglycemic effect but not immediate. In the long term treatment the plants’ crude root extractrnexhibited anti-diabetic effects on day 10 (p