This paper presents data which clearly reveal that the behavior model of young people in the Bosnian Serb Republic is characterized by an insufficient degree of information and poor knowledge on reproductive health, an increase in the number of alcohol consumers, drugs and cigarettes which leads to an increase in risky behavior, entering sexual relations and an earlier age, an increase in the number of sexually transmitted diseases and unwanted pregnancies which often result in abortions or premature birth. At the same time young people recognize the necessity for more information, mention competent authorities and expect help from them. At the same time, they show readiness to learn through peer education. On the other hand, the estimated results which we obtained by using available sources, because of the lack of a population census, give us information on the grave demographic situation in the Bosnian Serb Republic and negative tendencies in the future. When we speak of the total fertility rate and compare these data with countries of Europe and the surrounding areas, we can unfortunately only state that many factors - the most important being: war events, insecurity, unfavorable economic and social situation, significant migration of not only young people but of whole families - caused severely low total fertility rate in the Bosnian Serb Republic. Even worse, these tendencies are further decreasing and society is moving towards open depopulation with unforeseeable demographic, economic and national consequences. At the same time, it has been ascertained that young people are getting married at a later age, deciding on becoming parents at a later age and acting more riskily which decreases their fertility capacity and decreases their share in the total fertility capacity, making the already bad demographic picture of the Bosnian Serb Republic even worse.