Oil-and-gas potential of Cuba is ascertained by discoveries among which there are the most large-scale deposits, such as Boca de Jaruco and Varadero fields of heavy oils. Currently the petroleum and petroleum products needs of the island state are satisfied by own sources by less than a half. Prospects of the hydrocarbon resource base development are connected with the adjacent water area of the Gulf of Mexico where foreign companies have been granted license blocks for geological study and further development since 2001. Two Russian companies – JSC Gazprom Neft and OJSC Zarubezhneft among others took part in the development of the Cuban part of the Gulf of Mexico. Since 2004 5 oil wells have been drilled by various companies in deep water of the exclusive economic zone of Cuba. Commercial oil-and-gas bearing prospects have been established in neither of them for both geological and technological reasons. However, only a small part of the water area has been covered by drilling and the productivity of the drill core has been tested at the depth of Cretaceous sediments only. In our opinion, oil-and-gas bearing prospects of the exclusive economic zone of the Republic of Cuba in the Gulf of Mexico remain undervalued and the mentioned water area needs additional geological exploration. Planning of exploration work in this poorly explored region shall be carried out systematically and it shall be based on the results of the regional scientific research.