Of these, the largest is the Tigrinya, who make up around 50% of the population; the Tigre people, who also speak a Ethiosemitic language, constitute around 30% of residents.

):[12] The United Nations Department of Economic and Social Affairs (UN DESA) Population Division published its UN DESA 2019 Revision (World Population Prospects 2019) data release[13] based on several data samples, including the 1995 and 2002 Demographic and Health Surveys (1995 DHS, 2002 DHS) and the 2010 Population and Health Survey (2010 PHS), since a full census had not been carried out in Eritrea as of 2010[update].

[3]: 31 The 1995 DHS survey was carried out in Eritrea by the Eritrean National Statistics Office (NSO) and Macro International Inc., collecting data by interviewing 5,054 women aged 15–49 and 1,114 men aged 15–59, chosen to be a statistically representative sample, from September 1995 to January 1996.

[14] The 2002 DHS survey was carried out by the NSO (renamed as the National Statistics and Evaluation Office), with support from the United States Agency for International Development (USAID) and ORC Macro, collecting data with interviews of 8,754 women in Eritrea in the 15–49 age range, in what was considered to be a statistically representative sample of the full population.

[15] Key findings of the survey included a drop from 1995 to 2002 of fertility from 6.1 to 4.8 children per woman; improved knowledge of contraception; a drop in post-neonatal mortality; improved antenatal care; a doubling of the full vaccination rate for 12–23 month old babies from 41 to 76 percent; 38 percent of children under five years old were chronically malnourished or stunted; and near universal knowledge of HIV and AIDS.

[16] In 2010, the NSO, supported by the Fafo Institute for Applied International Studies, published a Population and Health Survey (EPHS2010), based on a survey covering 34,423 households by choosing 900 areas around Eritrea, 525 rural and 375 urban, and randomly selecting 40 households in each cluster.

The Guardian attributed the emigration to Eritrea being "a totalitarian state where most citizens fear arrest at any moment and dare not speak to their neighbours, gather in groups or linger long outside their homes", with a major factor being the conditions and long durations of conscription in the Eritrean Army.

[32] Factors corresponding to emigration include the "lack of political, religious and social freedom", economic reasons and indefinite military service.

[5] The East African Semitic languages spoken in Eritrea are Tigre, Tigrinya, and the newly recognized Dahlik.

The majority of the Tigrinya inhabit the highlands of Eritrea; however, migration to other parts of the country has occurred.

[4] The predominantly Tigrinya populated urban centers in Eritrea are the capital Asmara, Mendefera, Dekemhare, Adi Keyh, Adi Quala and Senafe, while there is a significant population of Tigrinya in other cities including Keren, and Massawa.

They are 92% Christians, (of which 90% are of the Eritrean Orthodox faith, 5% Roman Catholic and Eastern Catholic (whose mass is held in Ge'ez as opposed to Latin), and 5% belonging to various Protestant and other Christian denominations, the majority of which belong to the (Lutheran) Evangelical Church of Eritrea).

They are a predominantly Muslim nomadic people who inhabit the northern, western, and coastal lowlands of Eritrea, and constitute 30% of the country's population.

They are predominantly Muslim and are the only ethnic group in Eritrea to have Arabic as their communal language, specifically the Hejazi dialect.

[4] They are primarily concentrated in the north-central areas, in and around the city of Keren, and south towards Asmara, the nation's capital.

Many of them entered Eritrea from Kush (central Sudan) in the 8th century and settled at Merara, after which they went to Wag and Lasta.

Although some Kunama still practice traditional beliefs, most are converts to either Christianity (Roman Catholic and Protestant) or Islam.

According to the Pew Research Center (2010), 62.9% of the population are Christian, mostly followers of Eritrean Orthodox Tewahdo, and to a lesser extent, Roman Catholicism, with the second-largest religion being Muslims.

[40][6] In general, most local residents who adhere to Christianity live in the Maekel and Debub regions, whereas those who follow Islam predominantly inhabit the Anseba, Northern Red Sea, Southern Red Sea and Gash-Barka regions.