Census figure of country is used to determine the regional funding and the representation of religious and ethnic groups in the government. It provides some incentive for the inflation of local population. Figures of census were believed to have manipulated for the political advantage.

Large number of ethnic group in northern where 2/3rd of country is Hausa-Fulani, overwhelming majority of Muslim groups. Majority of Ethnic groups of north are Tiv, Nupe and Kanri.

Yoruba people are numerous in southwest. About half of Yorubas are the Christian and quarter is Muslims, remainder is mostly traditional beliefs. Predominantly Christian is largest ethic group in southeast, while Roman Catholic is largest ethnic group in southeast. Persons having different language backgrounds are most common in English. Population of country in year 2003 was estimated at 124,009,000 by United Nations that is placed as number 10 in the population among 193 nations worldwide. It is most populated in Africa . About 3% of population was over age of 65 years, in year 2003, another 44% of population under age of 15 years.

Estimation was there by population Bureau that near 44% of population lived in the urban areas in year 2001. Principal cities include in Lagos, former capital and are still largest city, estimated population in metropolitan areas is 13,488,000 and highest density of population with major African conglomeration, capital city had population of 403,000 in year 2003, while Ibadan had metropolitan population at 1,739,000 people, Kano had over one million and according to United States urban population rate of growth for years 2000 to 2005 was at 4.1%.