This report reviews and synthesizes country reports from Indonesia, Malaysia, the Philippines, Singapore and Thailand describing the state of knowledge on mangrove forests in this region. It describes the mangrove distribution and associations; including the occurrence of other species, both plants and animals, in mangrove areas. The physical and chemical, estuarine and oceanographic conditions of the environment are given as far as data could be found. The report then gives an overview of the most important pollutants in the region, and reviews the actual knowledge of effects on living aquatic resources. It points out the gaps where more knowledge is needed for the understanding of the effects of anthropogenic pressure on the mangrove ecosystems.