The continuous growth of energy consumption, intensive exploitation of non-renewable energy sources, geopolitical turmoil, global recession have resulted in the fact that the days of cheap energy are over. This paper discusses the problems and challenges the energy sector faces, with special emphasis on those related to the oil and gas sector in the world and in our country. Serbian energy policy objectives, established by the new Energy Law, include the promotion of energy security, energy efficiency, competitiveness of the energy market, use of renewable energy resources and environmental protection. With regard to each goal, a series of regulatory measures, programs and acts have been adopted that comply with the requirements of European energy regulations. What follows is an intense work on the implementation of the adopted measures and programs. In terms of the implementation of the energy development strategy, 'Naftna industrija Srbije' (NIS) is the most advanced. Therefore, the focus of this paper is on analyzing the development strategy of NIS in the context of the Energy Sector Development Strategy of the Republic of Serbia.