Medicinal plants have been used for centuries, and numerous cultures still rely on indigenous medicinal plants for their primary health care needs. Poisonous medicinal plants are used for various ailments such as Antidiabetic, Anticancer, Antibacterial, Antifungal, and Cytogenetic effect. The review reveals that wide numbers of phytochemical constituents have been isolated from the various medicinal plants which possess activities like diuretic, purgative, laxative, anti-allergic and various other important medicinal properties.