In 2001 Eritrea had an around population of 4,298,269, giving it a population density of 35 persons per sq km (92 per sq mi). An around 82 % of Eritrea’s population lives in rural areas, subsisting through agriculture and farm animal raising. The major cities of Eritrea include the capital and largest city Asmara, the seaports Massawa and Aseb, Keren, Nak’fa, Ak’ordat, and Teseney.

On the southern part of the coastal region live Afar nomads, whose relatives live across the borders in Djibouti and Ethiopia; they are also called the Denakil, after the region that they inhabit. The coastal strip south of Massawa, as well as the eastern flanks of the plateau, are occupied by Saho pastoralists. In the western plain, the dominant people are pastoralists of the Beja family, whose kin live across the border in The Sudan. Two small Nilotic groups, the Kunama and the Nara, also live in the west.

Eritrea's population comprises nine ethnic groups, most of which speak Semitic or Cushitic languages. The Tigrinya and Tigre make up four-fifths of the population and speak different, but related and somewhat mutually intelligible, Semitic languages. In general, most of the Christians live in the highlands, while Muslims and adherents of orthodox beliefs live in the lowland regions. Tigrinya and Arabic are the most often used languages for commercial and official transactions, but English is widely spoken and is the language used for secondary and university education.