People
Nationality: Noun and adjective--Congolese (sing. and pl.).
Population (2002): 3.2 million.
Annual growth rate (2002): 2.7%.
Ethnic groups: 15 principal Bantu groups; more than 70 subgroups. Largest groups are Bacongo, Vili, Bateke, M'Bochi, and Sangha. Also present is a small population (less than 100,000) of Pygmies, ethnically unrelated to the Bantu majority.
Religions: Traditional beliefs 50%, Roman Catholic 35%, other Christian 15%, Muslim 2%.
Languages: French (official), Lingala and Munukutuba (national).
Health: Infant mortality rate (2001)--81.0 deaths/1,000 live births. Life expectancy (2002)--51.6 yrs.
Work force: About 40% of population, two-thirds of whom work in agriculture.

Republic of Congo People
Congo's sparse population is concentrated in the southwestern portion of the country, leaving the vast areas of tropical jungle in the north virtually uninhabited. Thus, Congo is one of the most urbanized countries in Africa, with 85% of its total population living in a few urban areas; namely, in Brazzaville, Pointe-Noire, or one of the small cities or villages lining the 332-mile railway which connects the two cities. In southern rural areas, industrial and commercial activity suffered as a consequence of the civil wars. Except in Kouilou province and Pointe Noire, commercial activity other than subsistence activity came nearly to a halt. A slow recovery began in 2000.

Before the 1997 war, about 9,000 Europeans and other non-Africans lived in Congo, most of whom were French. Only a fraction of this number remains.
source: http://www.state.gov