Niger has the highest total fertility rate (TFR) of any country in the world, averaging close to 7 children per woman in 2022. A slight decline in fertility over the last few decades has stalled. This leveling off of the high fertility rate is in large part a product of the continued desire for large families. In Niger, the TFR is lower than the desired fertility rate, which makes it unlikely that contraceptive use will increase. The high TFR sustains rapid population growth and a large youth population – almost 70% of the populace is under the age of 25, as of 2020. Gender inequality, including a lack of educational opportunities for women and early marriage and childbirth, also contributes to high population growth.

Because of large family sizes, children are inheriting smaller and smaller parcels of land. The dependence of most Nigeriens on subsistence farming on increasingly small landholdings, coupled with declining rainfall and the resultant shrinkage of arable land, are all preventing food production from keeping up with population growth.

For more than half a century, Niger's lack of economic development has led to steady net outmigration. In the 1960s, Nigeriens mainly migrated to coastal West African countries to work on a seasonal basis. Some headed to Libya and Algeria in the 1970s to work in the booming oil industry until its decline in the 1980s. Since the 1990s, the principal destinations for Nigerien labor migrants have been West African countries, especially Burkina Faso and Cote d’Ivoire, while emigration to Europe and North America has remained modest. During the same period, Niger’s desert trade route town Agadez became a hub for West African and other Sub-Saharan migrants crossing the Sahara to North Africa and sometimes onward to Europe.

More than 60,000 Malian refugees have fled to Niger since violence between Malian government troops and armed rebels began in early 2012. Ongoing attacks by the Boko Haram Islamist insurgency, dating to 2013 in northern Nigeria and February 2015 in southeastern Niger, pushed tens of thousands of Nigerian refugees and Nigerien returnees across the border to Niger and displaced thousands of locals in Niger’s already impoverished Diffa region.