Abstract: The increasing prevalence of diabetes is reaching epidemic proportion worldwide. Diabetes is a major threat to global public health. World Health Organization defines diabetes mellitus as Aa metabolic disorder of multiple etiologies, characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. Many of the medicinal plants in use today, employed for the local management of diabetes mellitus do not have scientific validation including the stem-bark of Tamarindus indica. The stem-bark extract of Tamarindus indica is used locally for the management of diabetes. Acute toxicity test LD50 and phytochemical screening were conducted on the extract. The stem-bark extract of Tamarindus indica L. was investigated for its hypoglycaemic action on experimentally induced hyperglycaemic Wistar rats using dexamethasone (10 mg kg-1 SC for ten days) and fructose (10% w/v ad libitum for 20 days). The preventive effect of the extract on the development of insulin resistance was also investigated. The oral LD50 of the extract was found to be greater than 5,000 mg kg-1. Phytochemical screening revealed the presence of carbohydrates, glycosides, saponins, flavonoids, cardiac glycosides, tannins, alkaloids and triterpenes. The stem-bark extract of Tamarindus indica Linn significantly lowered elevated Blood Glucose Concentration (BGL) in fructose and dexamethasone-induced hyperglycaemia in experimental animal models. The extract also restored some of the altered lipid profile parameters and not much change was seen in the liver enzyme levels.