The article discusses the impact of demographic factors on the growth of radical sentiments in the society, the development of terrorism and extremism. Demographic factors include the qualitative and quantitative characteristics of the population, fertility and mortality, migration. The influence of demographic parameters on social processes, including the growth of radical sentiments in the society, the development of extremist and terrorist activities is shown in specific examples of developing countries, in particular the countries of Central Asia. The growth of extremism is directly linked to the demographic situation, which leads to major changes in the social structure and culture. The rapid increase in population, different levels of the fertility and mortality can facilitate the involvement of the population in a terrorist organization. So, poor and uneducated youth is much easier to radical ideas. These young people live in developing countries in Africa, the Middle East and Central Asia. An analysis of the demographic situation allows to predict the emergence of hotbeds of tension. Understanding the demographic situation contributes to the resolution of social problems, facilitates the fight against various manifestations of extremist activity.