Melia azedarach L., a species of the mahogany family (Meliaceae), has long been used as a folk medicine for various diseases. Recent studies on this plant revealed that this plant contains many interesting bioactivities such as antioxidant, antimicrobial, antiviral, antifeedant, antidiabetic, antifungal, and cytotoxic activities. A diverse range of organic compounds has been isolated from this species, such as triterpenoids, limonoids, degraded limonoids, steroids, lignans, flavonoids, and phenolics. This review article will give a comprehensive overview of the chemical constituents and biological activity of Melia azedarach.