Objective: To investigate the hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark (AETPB) in streptozotocin (STZ)-induced diabetic rats. Methods: Acute toxicity was studied in rats after the oral administration of AETPB to determine the dose to assess hypoglycemic activity. In rats, diabetes was induced by injection of STZ (60 mg/kg, i.p.) and diabetes was confirmed 72 h after induction, and then allowed for 14 days to stabilize blood glucose level. In diabetic rats, AETPB was orally given for 28 days and its effect on blood glucose and body weight was determined on a weekly basis. At the end of the experimental day, fasting blood sample was collected to estimate the haemoglobin (Hb), glycosylated haemoglobin (HbA1c), serum creatinine, urea, serum glutamate-pyruvate transaminase (SGPT), serum glutamate-oxaloacetate transaminase (SGOT) and insulin levels. The liver and kidney were collected to determine antioxidants levels in diabetic rats. Results:Oral administration of AETPB did not exhibit toxicity and death at a dose of 2000 mg/kg. AETPB treated diabetic rats significantly (P<0.001, P<0.01 and P<0.05) reduced elevated blood glucose, HbA1c, creatinine, urea, SGPT and SGOT levels when compared with diabetic control rats. The body weight, Hb, insulin and total protein levels were significantly (P<0.001, P<0.01 and P<0.05) increased in diabetic rats treated with AETPB compared to diabetic control rats. In diabetic rats, AETPB treatment significantly reversed abnormal status of antioxidants and lipid profile levels towards near normal levels compared to diabetic control rats. Conclusions: Present study results confirm that AETPB possesses significant hypoglycemic, hypolipidemic and antioxidant activities in diabetic condition.