The population of Nagaland consists of almost 2.2 million people, consisting of 1.04 million males and 0.95 million females. Among its districts, Kohima has the largest population (270,063) followed by Dimapur (170,000). The least populated district is Longleng (50,593). 75% of the population lives in the rural areas. As of 2013, about 10% of rural population is below the poverty line; among the people living in urban areas 4.3% of them are below the poverty line.
The life expectancy of Nagaland stands at 75.4 years, 79.9 years for females and 71.5 years for males (2019–21) while the infant mortality rate amounts to 3 per 1,000 births (2019), on par with the most developed countries. Both health indicators are the best among Indian states. The fertility rate of 1.7 children per woman (2019–21) lies below the population replacement level.
The state showed a population drop between the 2001 census and the 2011 census, the only state to show a population drop in the census. This has been attributed, by scholars, to incorrect counting in past censuses; the 2011 census in Nagaland is considered most reliable so far.