As the largest region in Thailand, the Northeast covers 20 provinces with a total population of around 22,700,000. Forty percent of the population is concentrated in the provinces of Khorat, Khon Kaen, Udon Thani, and Ubon Ratchathani. These four provinces surround the four major cities of the same names.

The region is mainly located on the Khorat Plateau, bordered by the Mekong River (along the border with Laos) to the north and east, by Cambodia to the Southeast. To the west it is separated from Northern and Central Thailand by the Phetchabun mountain range. Although it is called Khorat Plateau, the average elevation range is from 100 to 200 meters. There are three seasons each year. The rainy season is from May to October, the cool season from October to February, and the hot season from February to May. The average temperature range is from 30.2°C (86.4°F) to 19.6°C (67.3° F).

The Northeast has been transformed from one of the poorest region into Thailand's fastest growing economy. Agriculture is still the largest sector, which accounts for around 22% of the gross regional product (Compared to 8.5% for Thailand as a whole). Rice is the main agriculture crop. But farmers are increasingly diversifying into cash crops such as sugarcane and cassava, which are cultivated on a vast scale, and to a lesser extent, rubber. Silk production is an important cottage industry and contributes significantly to the economy. Since the 1970's, agriculture has been declining in importance as industry, commerce and service sectors have been developing fast.

The Northeast is also known as Isan, and famous for its unique culture, colorful tradition, beautiful national parks and mountains, and idyllic paddy fields. Isan food, in which sticky rice and chili peppers are prominent, is distinct from Central Thai cuisine.

The region has two main railway lines, both connecting Bangkok. One runs east from Khorat, through Surin to Ubon; the other runs north through Khon Kaen and Udon to Nong Khai. There are many highways across the region centering on the "Friendship Highway" which runs from Bangkok to Khorat, Khon Kaen, Udon Thani and Nong Khai. Major airports are at Udon Thani, Khon Kaen, and Ubon Ratchathani. Domestic air travel between Bangkok and the region is well developed, and has become the most convenient and fast way of travel.