This study evaluated Achyranthes aspera ethanolic extracts for their in vitro antioxidant activity and anti-hyperglycemic effects on alloxan-induced diabetic mice. Diabetes was induced in Swiss albino mice through intra-peritoneal administration of alloxan and their blood glucose levels and weight were measured weekly. At the end of the experiment, all animals were sacrificed and tissue samples were collected. A. aspera extracts had potent antioxidant activity compared to reference standard compounds. Treatment with an A. aspera extract at doses of 200 mg/kg and 400 mg/kg significantly reduced blood glucose levels in alloxan-induced diabetic mice. A. aspera extract also prevented lipid peroxidation as gauged by thiobarbituric acid reactive substances (TBARS) and hydroperoxides. Moreover, A. aspera extract increased the activity of catalase and reduced NO levels in alloxan-induced diabetic mice. Results revealed significant anti-hyperglycemic activity of A. aspera extracts in alloxan-treated mice that may be mediated by diminished oxidative stress.