Diabetes mellitus is a chronic disorder of carbohydrate, protein, fat and mineral metabolism. The antidiabetic potential of aqueous extracts flower and root of Aerva lanata was evaluated in alloxan induced diabetic rats. Alloxan (150 mg/kg bw) induced diabetic rats showed a hyperglycemic state that led to various biochemical and metabolic alterations. The aqueous extract of flower and root of A. lanata (200 mg/kg bw) was administrated orally to diabetic rats for 45 days. In this study, the levels of fasting blood glucose, glycated hemoglobin (HbA1C), C-reactive protein (CRP), total cholesterol, triglycerides (TG), low density lipoprotein (LDL), very low density lipoprotein (VLDL), urea, and creatinine were significantly increased in diabetic rats. Body weight, hemoglobin, insulin, C-peptide and protein levels in blood were significantly decreased in alloxan induced diabetic rats. After the administration of extracts of flower and root of A. lanata to diabetic rats showed significantly restore the levels as normal rats. The antidiabetic effect of A. lanata was compared with strandard drug glibenclamide (1 mg/kg bw) treated rats. From this study, we concluded that the aqueous extract of A. lanata root have more antidiabetic effect when compared with flower extract. Therefore, the flower and root of A. lanata may be used as the alternative medicine for the treatment of diabetes mellitus.