The ethnic Lao believe themselves to have originally inhabited an area that is present-day Dien Bien Phu in Vietnam. As they moved southwards they displaced the original inhabitants of the region, forcing them to resettle at higher elevations. The Khamu of northern Laos, speakers of a Mon-Khmer language, are the most numerous of the indigenes, but have assimilated to a high degree. A large spirit house located outside the village gates attests to the Khamu belief in animism.

Another Mon-Khmer-speaking group which inhabits the north, particularly Xainyabouli province, are the Htin . Owing to a partial cultural ban on the use of any kind of metal, the Htin excel at fashioning bamboo baskets and fish traps.

The Bolaven Plateau in southern Laos is named for the Laven people, yet another Mon-Khmer-speaking group whose presence predates that of the Lao. The Laven were very quick to assimilate the ways of the southern Lao. Other Mon-Khmer-speaking minorities found in the south, particularly in Savannakhet and Salavan include the Bru , who are skilled builders of animal traps; the Gie-Trieng , who are expert basket weavers; the Nge , who produce textiles featuring stylized bombs and fighter planes; and the Katu, said to be a very warlike people.