OBJECTIVE: To investigate the traditional antidiabetic uses of some indigenous Sudanese plants on streptozotocin-induced diabetes rats. METHODS: Diabetic rats were treated with a 400 mg/kg dose of aqueous extracts of five plant species orally for 2 h (acute) or 14 days (chronic). In acute model blood glucose levels were monitored at specific intervals. In the chronic model blood samples were collected from overnight fasted diabetic rats on day 15 to estimate blood glucose level. And the body weight, serum lipid profile and activities of liver and kidney enzymes were measured. Histopathological observations of liver sections were also studied. RESULTS: In the case of acute treatment, aqueous extracts of Tinospora bakis (T. bakis), Nauclea latifolia (N. latifolia) and Randia nilotica (R. nilotica) at 400 mg/kg significantly lowered (P < 0.05) blood glucose levels in diabetic rats whereas, chronic treatment of diabetic rats with 400 mg/kg of T. bakis, N. latifolia, R. nilotica and Mitragyna inremis proved to have significant (P < 0.05) antihyperglycemic effect and have the capacity to correct the metabolic disturbances associated with diabetes. Histopathological studies showed that the aqueous extracts of these four plants reinforced the healing of liver. However, Striga hermonthica aqueous extract did not exert any antihyperglycemic effect to diabetic rats. CONCLUSIONS: This study demonstrated that T. bakis, N. latifolia, R. nilotica and Mitragyna inremis have therapeutic value in diabetes and related complications and thus supporting the traditional uses of these plants in Sudanese traditional medicine.