Abstract: The miracle medicinal plant Morinda citrifolia L., also called as Noni, Great Morinda or Indian mulberry, belongs to the family Rubiaceae. Its fruit has been used traditionally for more than 2000 years by native Polynesians. However, all parts of the plant have medicinal properties. More than 160 phytochemicals have been isolated from the plant Noni which makes it an amazing herbal remedy for the treatment of numerous disorders including cancer. Recently, the Noni juice has been in high demand in market as Complementary and Alternative Medicine (CAM) for its multi-dimensional health benefits. It is a potent antibacterial, antiviral, antifungal, antihelminthic, anticancer, analgesic, anti-inflammatory, anti-oxidant, hypotensive, cardiovascular protective, wound healer, anxiolytic, sedative, antigout, antiobesity and immune enhancing agent. Anticancerous activity of Morinda citrifolia is attributable to its anti-inflammatory, antioxidant and apoptosis-inducing effects. Based on toxicological and mutagenicity assessment, Noni juice has been considered as safe. Few reports of hepatotoxicity exist, although there are many evidences suggesting hepatoprotective effects of Noni. Even though large number of in vitro studies has been carried out but only few clinical trials exist in the literature to suggest real beneficial effects of Noni in humans. Recently, Noni fruit juice has been accepted as a novel food element in the European Union. A number of scientific studies have been conducted to elucidate the mechanism of action of phytoconstituents of Noni. In this review, active phytochemical constituents, pharmacological properties, mechanism of action and various immunomodulatory and therapeutic potentials of Noni usage as a useful herbal medicine are discussed in detail which could be very helpful in safeguarding health of humans and their companion animals. A special focus has been made on the potent utility of this wonderful herbal plant in preventing and treating the deadly malady of cancer.