This paper focuses on the relations between Serbia and NATO in the period after the unilateral declaration of independence of Kosovo and Metohija and gives an analysis of military neutrality of Serbia, future development of the relations between NATO and Serbia and discussion of whether (and if so, how) the development of relations would affect ties between Serbia and Russia. The author poses and, based on many sources from domestic and foreign authors, attempts to give a reasonable answer to the question what Serbia would lose and what it would gain by becoming a member of NATO. How would Serbia's membership in NATO reflect on its relations with Russia, USA and countries in the region? Is Serbia's military neutrality possible and if so, if implemented in reality and practiced in the way that other militarily neutral countries practice it, how would it affect the security situation in the region and in the world? How did the military intervention of NATO against Serbia reflect onrelations between Serbia and NATO and Russia and NATO?