The present study was undertaken to evaluate antidiabetic and antioxidant activities of Cassia tora (C. tora) seeds extract against streptozotocin induced diabetes in experimental rats to scientifically validate its use against diabetes. Ethanolic extract of C. tora seeds extract and standard drug (glibenclamide) prepared in aqueous gum acacia (2 %, w/v) suspension and fed orally to streptozotocin induced male adult diabetic rats of Charles Foster strain for 15 days. Biochemical parameters in normal, diabetic control, standard (600 μg/kg bw p.o.) and treated (500 mg/kg bw p.o.) animal groups were quantified and compared. Treatment of streptozotocin induced diabetic rats with ethanolic seeds extract caused significant (p < 0.001) reduction in blood glucose (270-220 mg/dl), total cholesterol (140-104 mg/dl), triglyceride (149-99 mg/dl), phospholipids (100-74 mg/dl), free fatty acid (2.39-2.00 μmol/l), lipid peroxide (9-5.63 nmol MDA/dl) and significantly increased post heparin lipolytic activity (11-14 nmol FFA released/h/l plasma) (p < 0.001). Furthermore, the seeds extract (100-400 μg) when tested for its antioxidant activity in vitro, showed significant (p < 0.001) inhibition in the generation of super oxide anions in enzymic system a (46-37, 33, 23, 21 nmol uric acid formed/min), in enzymic system b (113-91, 77, 60, 51 nmol formazon formed/min), non-enzymic system (324-230, 211, 161, 141 nmol uric acid formed/min) and hydroxyl radicals in enzymic system (544-501, 411, 319, 291 nmol 2,3-dihydroxybenzoate formed/h) and non-enzymic system (28-21, 17, 14, 12). The results of the present study demonstrated antidiabetic, antidyslipidemic and antioxidant activities of C. tora seeds which could help in prevention of diabeticdyslipidemia and related complications.