This review represents the studies performed on some beneficial mangrove plants such as Ceriops decandra, Xylocarpus granatum, Xylocarpus moluccensis, Excoecaria agallocha, Sarcolobus globosus, Sonneratia caseolaris and Acanthus ilicifolius from the Sundarban estuary spanning India and Bangladesh with regard to their biological activities and chemical investigations till date. Sundarban is the largest single chunk of mangrove forest in the world. The forest is a source of livelihood to numerous people of the region. Several of its plant species have very large applications in the traditional folk medicine; various parts of these plants are used by the local people as cure for various ailments. Despite such enormous potential, remarkably few reports are available on these species regarding their biological activities and the active principles responsible for such activities. Though some chemical studies have been made on the mangrove plants of this estuary, reports pertaining to their activity-structure relationship are few in number. An attempt has been made in this review to increase the awareness for the medicinal significance as well as conservation and utilization of these mangrove species as natural rich sources of novel bioactive agents.