Abstract: Stevia rebaudiana Bertoni is a sweet tasting medicinal herb; its leaves are rich source of sweetener "steviosides", which are up to three hundred times sweeter than sucrose, more than half of which is composed by Stevioside and Rebaudioside. Due to its sweet taste it has high commercial value throughout the world as sugar substitute in medicine, foods products and beverages. The increased market share of Stevia sweeteners has established a lasting increase in the demand for constant high quality and high purity of Stevia products. Clinical examinations performed on Steviol glycosides have shown that it is non toxic and exert hypotensive, cardiotonic, anti-diabetic, anti-carcinogenic, anti-inflammatory, anti-viral and anti-bacterial actions. Stevia leaves, steviosides and highly refined extracts of the leaves are now officially used as a low calorie natural sweetener and dietary supplement in many countries. In future, there is possibility that Stevia could become a major source of high potency low calorie sweetener for growing demand in natural food market. This manuscript focuses on the phytochemistry, medicinal applications, pharmaco kinetics and safety evaluations of Stevia products. Besides this, recent developments in agricultural breeding, biotechnological approaches through cell and tissue culture, improved extraction procedures and biotransformation for taste improvement in S. rebaudiana have also been discussed. Future prospects for realization of commercial production of Steviol glycosides are critically evaluated.