Alloxan administration in male albino rats, induced diabetes by increasing blood glucose concentration and reducing hepatic glycogen content as compared to normal control group. Besides, serumlipid profile parameters such as total-cholesterol, triglyceride, low-density lipoprotein and very lowdensity lipoproteincholesterol were also elevated, whereas, the level of high-density lipoprotein-cholesterol was reduced significantly (P<0.05) in diabetic rats. Treatment of diabetic animals with hot aquous extract of Hydroclathrus clathratus for 30 days, significantly lowered blood glucose level, elevated hepatic glycogen content and maintained body weight and lipid-profile parameters towards near normal range.. Declined activityof antioxidant enzymes and concentration of non-enzymatic antioxidants were also normalized byHCE treatment, thereby reducing the oxidative damage in the tissues of diabetic animals and hence indicating the anti-diabetic and antioxidant efficacy of the extract. Biochemical observations were further substantiated with histological examination of liver and pancreas.