The main objective of this study is to estimate the land surface soil moisture conditions in the Mekong Delta (MD), Vietnam using MODIS data (acquired from January to April in 2007). The data was processed using the temperature vegetation dryness index (TVDI). The index was computed by empirically parameterizing the relationship between the MODIS land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) data. The results indicate that the LST-NDVI space was well-defined to form a triangle, indicating a wide range of soil moisture conditions in the MD. The TVDI validated by comparison with daily rainfall data shows that TVDI is, in general, sensitive to daily rainfall data. The high TVDI values indicating low soil moisture patterns were spatially distributed in the northeast and coastal areas from January to mid February (or DOY 49), where single and double rainfed rice cropping was typically practiced. The low soil moistures were however expanded into the middle region after DOY 49, where double and triple irrigated rice cropping systems were practiced.