Thuja occidentalis belongs to the Cupressaceae family, referred to as Thuier cedar, 

American cedar, Cedrethuya occidental, white eastern cedar, American or eastern arborvitae, 

tree of life. It is predominantly nurtured in the European region. Thuja is used as a medicinal plant in traditional medicine such as homeopathy because of its therapeutic application. Thuja occidentalis contain essential oils, coumarins, and flavonoids. This chapter focuses on the chemical constituents and bioactives of T. occidentalis. The pharmacological aspect of Thuja exhibits antioxidant, anti-inflammatory, antibacterial, antifungal, antiviral, anticarcinogenic, gastroprotective, and antipyretic activity. Furthermore, Thuja can also regulate glucose and lipid metabolism and possess protective effects against radiation-induced toxicity. These medicinal and therapeutic applications render Thuja to be used for preventing and treating various pathologies in humans. 

Keywords: Thuja occidentalis; Bioactives; Pharmacological aspects; Protective effects; Therapeutic and Medicinal uses.