Stevia rebaudiana Bertoni is a perennial herb native to South America and commonly known as "stevia." The leaves of stevia have been used for centuries in Paraguay and Brazil to sweeten food and beverage. Nowadays, the leaves of stevia and the steviol glycosides extracted from them are commonly used to sweeten beverages and foods. The steviol glycosides are a non-nutritive substitute of sugar that does not provide energy. Besides their sweetening properties, the antioxidant capacity of stevia and its sweet diterpenes are reported in the literature. This chapter aims to review the antioxidant properties of S. rebaudiana reported in the literature, the future directions on this topic is discussed taking into consideration its implication on human health. Keywords Stevia • Stevioside • Reb A • Antioxidant activity in vitro • Antioxidant activity in vivo Abbreviations ABTS 2,2 0-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) CAA Cellular antioxidant activity CQA Caffeoyl quinic acid DPPH 1,1-diphenyl-2-picrylhydrazyl radical EFSA European food safety authority FRAP Ferric reducing/antioxidant power GPx Glutathione peroxidase GR Glutathione reductase GSH Reduced glutathione JECFA Joint FAO/WHO expert committee on food additives ORAC Oxygen radical absorbance capacity Ox-LDL Oxidized low density lipoprotein Reb A Rebaudioside A ROS Reactive oxygen species SCF Scientific committee for food SOD Superoxide dismutase