The dominant ethnic group is the Lao Loum (Lowland Lao), who through superior numbers and living conditions - in the fertile plains of the Mekong River valley or lower tributaries of the Mekong - have for centuries domi­nated the smaller ethnic groups living in Laos. Their language is the national language; their religion, Buddhism, is the national religion; and many of their customs - including the eating of sticky rice and the bqasii ceremony  - are interpreted as those of the Lao nation, even though they play no part in the lives of many other ethnic groups.

Lao Loum culture has traditionally consisted of a sedentary, subsistence lifestyle based on wet-rice cultivation. They live in raised homes and, like all Austro-Thais, are Theravada Buddhists who retain strong elements of animist spirit worship.

The distinction between 'Lao' and 'Thai' is a rather recent historical phenomenon, especially considering that 80% of all those who speak a language recognised as 'Lao' reside in northeastern Thailand. Even Lao living in Laos refer idiomatically to different Lao Loum groups as 'Thai', for example, Thai Luang Phabang (Lao from Luang Prabang). See also Lifestyle .