This paper summarizes the results of the detection of tsunami damaged areas in south Thailand using remote sensing data. The area was hit by a series of tsunamis caused by the 26 December, 2004 North Sumatra Island Earthquake. According to the tsunami reconnaissance survey conducted in January, 2005, vegetation was observed to be decreased in damaged areas. Therefore, NDVI (Normalized Difference Vegetation Index) was expected to be useful to assess inundation areas. Considered the scale of the disaster, ASTER data with 15m spatial resolution was chosen for NDVI analysis. Moreover, SRTM data and high-resolution satellite images were used for verification of the estimated inundation areas.