This article is devoted to the study of existing problems and prospects for the development of cooperation between the Russian Federation and Mongolia in the field of electric power. The author briefly describes the history of the development of Russian-Mongolian relations in this area and current legal framework, another point of interest is the study of existing energy problems in Mongolia. Particular attention is paid to the advantages that the Russian side has in its energy cooperation with Mongolia. The author then analyzes the areas of cooperation between Russia and Mongolia in the field of electric power, specifically: thermal energy (the most important traditional area), development of electrical grid infrastructure, hydropower, nuclear energy and, finally, alternative energy. For each area, the author provides information about the degree of its development in Mongolia and the opportunities available to the Russian side while interacting with Mongolian partners. The article provides a list of the most significant, including those already implemented, those under development, or those with a promising future. In addition, the author studies the existing problems that hinder the deepening of Russian-Mongolian cooperation in the electric power industry, such as opposition from other states (primarily the so-called «third neighbor» countries) and unresolved contradictions regarding Mongolian hydroelectric power station projects in the Selenga River basin. The author concludes that if the Russian side properly realizes the available advantages, there are good chances to resolve the controversial issues and achieve success in the development of Russian-Mongolian cooperation in the electric power industry, thereby contributing to economic growth and strengthening energy security of both countries.