The paper studies the importance of demographic processes on the territory of Sandžak in the period of 1948-1991 in the context of demographic causes of Great-Serbian aggression against Croatia and Bosnia and Herzegovina in 1991 and Serbian military activities in Kosovo and south-east of Serbia (Preševo and Bujanovac districts).It has been presumed that the religious and national structure of Sandžak with a further trend of the increase of absolute number and relative share of Moslems and decreasing number of Serbians and Montenegrins, as well as considering its geostrategic importance to Serbian and Montenegrin interests then those of international power centres, will continue to be the causal space of potential crises and war conflicts not only in the quoted country but in the larger region too. As it is a question of nearer Croatian security environment, the territory of Sandžak is important also from the viewpoint of national security of the Republic of Croatia.