The wind energy potential of Thailand was evaluated by using an atmospheric mesoscale model and a Geographic Information System (GIS) approach. The Karlsruhe Atmospheric Mesoscale Model (KAMM) was used to calculate hourly wind speed in Thailand over the period of 15 years (1995–2009) with a horizontal spatial resolution of 3×3 km2. Input data consisted in vertical profiles of wind velocity, air temperature and relative humidity obtained from radiosonde soundings at four meteorological stations as well as roughness and terrain elevation taken over the entire country. The values of hourly wind speed were averaged to obtain the mean monthly and mean yearly wind speeds. Values of mean monthly wind speed calculated from the model were compared with those obtained from the measurements at four sites typifying the main climatic regions of the country. Measured and estimated values of the mean wind speed were in reasonable agreement, with a Root Mean Square Error (RMSE) of 9.3%. The model was run to estimate mean annual wind speeds at 100 m above ground level and results were displayed as a wind resource map. This map was incorporated into a GIS computer program. Digital maps of land-use and prohibited areas for the installation of wind turbines (e.g. urban areas, national parks and reserved forests) were also used as input into the program. With a given set of criteria, areas which have high potential for wind energy development were quantitatively identified.