The myrtle family, Myrtaceae, constitutes over 5500 species, and Syzygium is considered the largest genus of the flowering plants within the family. The watery rose apple, Syzygium aqueum, is a traditional medicinal plant with various bioactive compounds distributed in all plant parts. These include phenolic compounds, flavonoids, tannins, terpenoids, and essential oils. S. aqueum extracts and their isolated compounds showed multiple beneficial biological effects such as antibacterial, antifungal, antidiabetic, analgesic, antimalarial, antioxidant, anti-inflammatory, and anticancer activities. This review is aimed at discussing all the available information about the nutritional value, traditional uses, and therapeutic properties of the leaves, fruit, and stem bark of the plant, in addition to the distribution of phytoconstituents in its different parts as well as recommend future research directions on this species to promote its clinical uses.