Susceptibility of Asian megadeltas to climate change, including sea-level rise, is investigated using GIS. The Indus, Ganges-Brahmaputra-Meghna, Irrawaddy, Chao Phraya, Mekong, Red, Pearl, Changjiang, and Huanghe deltas began to form around 6000 years ago and have prograded since. The surface topography of active and abandoned delta plains is examined using digital terrain models derived from Shuttle Radar Topography Mission data and channel morphology is investigated using radar imagery. After delta plains are abandoned they become increasingly dominated by tidal processes. Population density is estimated using gridded world population data but highly variable local microtopography and uncertainty regarding future climate changes preclude detailed vulnerability analysis.