Strychnos nux-vomica L. (Loganiaceae), is a deciduous tree, that has been traditionally used in the traditional medicinal systems of Ayurveda, Unani and Chinese medicine. Its seeds have been employed to treat neurological disorders, arthritis, and digestive ailments. The ca. eighty bioactive compounds identified in S. nux-vomica; include the alkaloids strychnine and brucine as major components. They are potent central nervous system stimulants that exhibit both therapeutic effects and dose-dependent toxicity. Further important biologically active compounds isolated from different parts of the plant are iridoids and flavonoid glycosides, triterpenoids, and organic acids. These have anti-inflammatory, analgesic, antimicrobial, antioxidant, antitumor, antidiabetic, and bone-regenerative effects. Despite its medicinal value, the potential toxicity of the drug necessitates careful use and underscores the importance of proper detoxification methods. This chapter reviews current knowledge of the plant’s botany, ethnobotanical claims, traditional uses, phytochemical composition, pharmacological properties, and toxicology.