Rhizophora mangle L. (red mangrove) is a species that grows primarily in humid tropical areas. In addition to providing important ecological functions, it has been also used in traditional medicine for the treatment of several ailments. Among its therapeutic properties, antiseptic, antifungal, antibacterial, antioxidant, antiulcer, wound healing, hypoglycemic, and anti-inflammatory activities are reported. Moreover, extractions and partitions obtained from different parts of the species have proven to have a wide range of biological activities that could positively impact human health. The bark and leaves have been chemically characterized and have been identified as sources of potentially bioactive polyphenols. This chapter aims to summarize the most significant findings on the phytochemical composition and biological activities of R. mangle over the years.