The People's Democratic Republic of Laos is a landlocked country, bordered to the north by China, to the west by Myanmar, to the east by Việt Nam and to the south by Thailand and Cambodia. It covers a total land area of 235,000 square kilometres (an area slightly larger than Great Britain), some 70 per cent of which is made up of mountain, highland and plateaux.

Southern and central Laos lie just to the west of the Annam Highlands, a formidable mountain range with an average height of 1,200 metres which has long divided the indianised and sinitic civilisations of the region. All tributaries west of this range drain into the Mekong River, which forms a large part of the border with Thailand and continues on through Cambodia and southern Việt Nam into the South China Sea. The Mekong and the tributaries which flow into it have always been at the heart of Lao civilisation and culture, indeed most of the country's population lives in the fertile plains in their immediate vicinity.