Medicinal plants are receiving much attention because they are traditionally used to treat common diseases. Syzygium polyanthum, an important medicinal plant, has been widely used in Southeast Asia, and numerous studies have published its chemical constituents and biological properties. Therefore, this study aimed to present the results of previous studies on extraction methods, chemical contents, and bioactivities of S. polyanthum published between 2011 and 2023. Some solvents have been predominantly used in the extraction of S. polyanthum, such as methanol, ethanol, ethyl acetate, n-hexane, and water. Maceration was the most commonly used method, followed by Soxhlet extraction, hydro-distillation, percolation, decoction, infusion, ultrasound-assisted extraction, and rapid solvent extraction. Furthermore, bioactivities of S. polyanthum, such as antioxidant, antihypertensive, antihyperglycemic, antibacterial, antifungal, cytotoxic, and antidementia properties, were reported. However, in the toxicity studies, no toxicity signs were observed after extended administration. Therefore, S. polyanthum might be an alternative natural product in treating some diseases. It also might be the main therapy when appropriate extraction method and solvent are used.